After unveiling what's next for the most popular Windows Live client application, Messenger, and the most popular Windows Live web service, Hotmail, Microsoft is now ready to zero in on (most of) the remaining client applications in the Windows Live Essentials suite.

The Windows Live Essentials team says it focused on updating the applications in a way that complements Windows 7 (and still works on Vista, but not XP). Specifically, Microsoft says it focused on making three tasks easier: creating and sharing polished photos and movies with your closest friends, organizing your e-mail accounts in one place with flexible tools to be productive, as well as synchronizing files across your computers and accessing them from virtually anywhere with an Internet connection. Microsoft is focusing on sharing so much because it says 60 percent of PC users share photos weekly and 25 percent edit and share videos. At the same time, though, 50 percent of photos and 80 percent of videos that users take don't get shared because they find it too hard to do so.

The Wave 4 release of Essentials still includes Windows Live Messenger, Windows Live Mail, Windows Live Writer, Windows Live Photo Gallery, Windows Live Movie Maker, and Windows Live Family Safety. Windows Live Sync has received a major update and is now part of the suite. The Windows Live Toolbar, meanwhile, has been replaced with the Bing Bar.

As we saw with the Wave 4 Milestone 2 leak, there are a lot of changes coming for each application, but Microsoft is only interested in outlining the features in Messenger (already previewied in April), Mail, Photo Gallery, Movie Maker, and Sync.

"While you'll see updates across all Windows Live Essentials applications in this release, we prioritized our investment in five primary applications based on the feedback we've received from our customers," a Microsoft spokesperson told Ars. "We don't have any specific details to share right now about the [other three] applications." In other words, there aren't many changes to expect for Windows Live Writer, Windows Live Family Safety, or the Bing bar. Here's what Microsoft is willing to share:

Windows Live Mail

Mail is still all about managing multiple e-mail accounts, calendars, RSS feeds, contacts and newsgroups in one place. Offline access has been improved to encompass e-mails sent or calendar edits made while offline: they're queued up and synced next time you get an Internet connection. Shared calendars can also be accessed, viewed, and edited right from the program. Windows Live Messenger integration means that you'll be able to reply to a contact with an instant message right from the program since you can see their online status in the e-mail header.

As for inbox management tools, there's conversation-threading (different views for organizing messages) and quick views (filters that help you find certain items, such as unread mail from contacts only, flagged e-mails, all mail across inboxes, and so on) for all your e-mail accounts, newsgroups, and feeds. As we've seen in leaked screenshots, you can now view your calendar without navigating away from the context of your inbox (Microsoft is calling this Slim Cal). Finally, Windows Live Mail will let you send up to 10GB worth of photos via a link in one e-mail (pictured above). You can also add captions, layouts, and edit your photos directly while composing your e-mail.

Windows Live Photo Gallery

Photo Gallery is getting two very useful features: 1) Photo Fuse allows you to take the best parts of multiple photos to combine them into one "perfect" photo with an easy-to-use editing tool (pictured above), and 2) facial recognition technology finds pictures with people in them and deduces who is in those pictures based on who you have tagged in past pictures (pictured below).

In addition, there are two new editing features: retouch, which help you remove things like blemishes, scratches, bruises, or stains from pictures, and batch auto adjust, which fine-tunes your photos' exposure, color balance, and sharpness. As for the actual program, the new Find Tab allows you to naturally filter your photos by faces, names, dates, geo-locations, descriptive tags, folder titles, or any combination of those, and the import feature works with Windows 7 to easily get photos and videos off your devices and organize them on your computer.

Windows Live Movie Maker

Movie Maker is getting AutoMovie themes (pictured above). AutoMovie will add a theme, which includes transitions, a title, captions, and a music soundtrack, to your photos and videos. These same themes will be available in Photo Gallery's slideshow mode.

Movie Maker is also getting better at editing audio and video: tailor your movie's soundtrack or trim a video clip from either end. The program can save in high-definition formats (720p and 1080p) or to a portable device, such as a Windows phone or Zune HD player. Sharing online on Facebook, Flickr, YouTube, or SkyDrive is built-in, and there will be plug-ins for other online sharing sites (pictured below). Some of this you've already seen in Movie Maker 14, the most recently updated Windows Live application.

Windows Live Sync

Sync lets you synchronize folders across your PCs and Macs. Update a file on one computer, and it will automatically sync to the rest when they're turned on and connected to the Internet. Once your folders are synchronized, everything is available offline. There's also a remote desktop feature: leave your PC online, and you can access its files and apps from devices.live.com (news of this one leaked back in August 2009 by finding your PC among the list of devices and clicking "Connect to this computer."

What's next?

Microsoft is still refusing to share when it expects to release Windows Live Wave 4. A Microsoft spokesperson did, however, tell us that "tonight is only a preview, and the betas will be released in the coming months." Rumors have placed the public beta somewhere between the weeks of June 7, 2010 and June 21, 2010. That's for Windows Live Essentials, meaning the client applications. But what about the web services? Hotmail could start getting updated as soon as mid-month, but don't hold your breath, as rollouts as large as this one tend to be done gradually. The final release of Wave 4 should be done by the time we see Windows 7 Service Pack 1.