During a special media event held today in Cupertino, Apple unveiled details about the next major update to the iPhone OS that powers its iPhone, iPod touch, and iPad mobile devices. Slated to arrive sometime this summer for the iPhone and iPod touch, the update will give developers access to over 1,500 new APIs to improve and extend the capabilities of their apps, as well as give users over 100 new features like multitasking and improved enterprise support.

Apple CEO Steve Jobs detailed seven major new features that he described as "tentpoles" for the OS. Addressing the number one request of most users is a new app multitasking system. Jobs explained that implementing multitasking is easy if battery life and application performance isn't a concern, but Apple has taken its time to develop a system that it says avoids these common pitfalls. "We weren't the first to this party, but we're going to be the best," Jobs said.

Multitasking

Senior vice president of iPhone software engineering Scott Forstall offered up more details. Apple looked at thousands of apps to determine what services apps would most need to keep running while in the background. "In iPhone OS 4, we're providing those services as APIs to developers," Forstall said. That way, iPhone OS can manage those services to best optimize battery life and performance.

Pandora founder Tim Westergren was on hand to demonstrate a version of Pandora that took advantage of these APIs, showing off one of the most sought-after uses for multitasking. Westergren played streaming music from Pandora while switching over to iTunes to buy a song he liked, and the stream kept playing as he shopped.

Other potential uses for background processes were demonstrated or discussed, such as keeping Skype active to receive VoIP calls, or allowing GPS apps like TomTom to continually track your location. Forstall also discussed an alternative to continuous GPS tracking, which can wear down the battery. An app such as Loopt or Foursquare can register to be notified when an iPhone detects that it has switched to a different cell tower. The app can then be activated and the GPS hardware polled for your new location.

Noting privacy concerns, Forstall revealed a system-wide notification that reveals which apps have requested location data. That will prevent any app from using your location data without your knowledge, and should discourage any developer from trying to do so.

In addition to audio, VoIP, and background location, Forstall also discussed some other background services that developers can add to their apps such as push notifications, local notifications, task completion, and fast-app switching. This last feature lets any application freeze its state so that it idles without using any CPU resources. When the app is switched back to the foreground, it continues running as if nothing happened.

Folders

Apple detailed some new features for the iPhone OS's Springboard launcher. You can add custom backgrounds for both the lock screen and the home screen, just as you can on the iPad. For those with a growing library of apps looking for a new way to organize them, iPhone OS now has folders. Apps can be dragged on top of each other to create a folder, and other apps can be added. Folders can be placed in the Dock for quick access to a group of apps, as well. With folders, users can cram up to 2,000 apps onto their devices.

Mail

Mail will get a number of longed-for improvements in iPhone OS 4.0. Apple has finally added a unified inbox to Mail, so those of you setting up multiple e-mail accounts on your iPhone can see all your mail at once without switching accounts. Business users will likely applaud the ability to add more than one Exchange account. And Apple made switching between different inboxes much faster.

Other improvements include a threaded message view, which keeps related replies together, and the ability to open mail attachments if you have an app installed that can handle a particular file type.

iBooks for the iPhone and iPod touch

Apple is also making a version of iBooks that will work on iPhone and iPod touch. It's essentially a miniature version of iBooks for iPad, replete with the bookshelf and access to the iBookstore. You'll be able to access the same library of books from any of your iDevices, and bookmarks and last pages will wireless sync between them.

Enterprise

Jobs noted that 80 percent of Fortune 100 companies are using iPhones in some way with the blessing of their IT departments. One new enterprise-friendly goody coming in iPhone OS 4.0 is new data encryption features. Users will be able to encrypt their e-mail and attachments using a PIN code. And developers will have an API to encrypt data within their own apps.

iPhone OS 4.0 will also give IT admins mobile device management, and they'll be able to distribute apps wirelessly to mobile devices without relying on iTunes syncing. In addition to multiple Exchange account capabilities, Apple is adding Exchange Server 2010 support. And there's also support for SSL-encrypted VPN sessions with Juniper and Cisco infrastructures.

"Game Center"

Apple is building its own "social gaming network," akin to Open Feint and Ngmoco's Plus+, that developers can include support for in their games. In addition to leaderboards and achievements, it will offer a standardized way for players to "challenge" each other to best one another's scores. Apple is including a feature to automatically find other players of similar ability with a particular game, sparing novices the embarrassment of being trampled by a more experienced player.

Open Feint, Plus+, and other networks have a dedicated following among some developers (and certainly many players), so whether or not Game Center will see wide adoption is uncertain. But during a Q&A following the presentation, Jobs noted that developers had asked for Apple to develop its own social network. "There's no money to be made and no advantage to us to having a social gaming network, so everyone should just say 'great, less work for me'," he said.

iAd

Jobs spent a good chunk of the event discussing the seventh "tentpole"—a centralized mobile ad network called (as rumored) "iAd." Developers will have APIs to add support for ads into their apps, and Apple (via its acquisition of Quattro Wireless) will handle all the necessary ad sales.

The ads will help support free apps, and developers will get an "industry standard" 60 percent of ad revenue. Jobs noted that Apple will soon have as many as 100 million mobile devices running iPhone OS in the wild, offering as many as 1 billion advertising opportunities per day. "This is a pretty serious opportunity," Jobs noted, while saying that a lot of current mobile advertising "just sucks."

Jobs said that iAd will offer advertisers a way to add the "emotion" that video ads on TV often have, but that Web and mobile advertising currently lacks. That includes building interactive ads using HTML5, CSS3, and JavaScript. He then demoed ads that Apple built to show off what iAd could do, including ones for Toy Story 3, Air Jordans, and Target.

Perhaps the best announced feature of iAds, though, is that it doesn't take you outside of the app you're using to view the ads. Dismiss the ad whenever you want, and you're right back where you left off.

Availability

iPhone OS 4.0 will be available this summer for iPhone and iPod touch. The latest devices—the iPhone 3GS and the 3rd-gen iPod touch—will get all the features mentioned today and more. The previous generation—iPhone 3G and 2nd-gen iPod touch—should get "most" of the features, but unfortunately that doesn't include multitasking (Boo!). The original iPhone and iPod touch will get nothing and like it.

iPad owners, which already have a few of the features in iPhone OS 4.0, will be able to upgrade in the fall.

Developers can download a preview of iPhone OS 4.0 starting today, to get access to the 1,500 new APIs and begin the process of adding support for the new features before 4.0 launches this summer.

Other tidbits

During the announcement, Jobs also briefly detailed some impressive sales numbers for the first few days of the iPad's availability. So far, Apple has sold 450,000 iPads. Users have purchased over 3.5 million iPad apps and 600,000 e-books from the iBookstore. The number of iPad-specific apps in the App Store is over 3,500 and counting.

During the Q&A session, Jobs reiterated Apple's position on adding Flash or Java support for its mobile devices. In a word, "no," it's not happening.

The iPad also came up. The response to the iPad has been "beyond belief" according to SVP of worldwide marketing Phil Schiller. Jobs said that he received several thousand e-mails praising the device, and that he isn't worried about competitors moving in anytime soon, either. "If our competitors ever produce a competitive product to iPad, they'll be hoping they can get 3,500 apps after the first year, and we've seen that in less than a week," he said.