Apple has formally announced its upcoming media event after months of rumors and speculation. The event will take place on Tuesday, October 4 at 10am Pacific Daylight Time on Apple's campus in Cupertino—just as the latest rumors predicted—and will be led by Apple's new CEO Tim Cook.

Apple's invitation graphics (shown above) include four iOS app icons (Calendar, Clock, Maps, and Phone) along with the quote "Let's talk iPhone." Apple doesn't usually get this specific when sending out its invitations, but apparently it's trying a new, more direct approach this time around. (As an aside, the icon choices are quite clever. The calendar says October 4, clock says 10:00, map points to Apple's campus, and the phone icon shows one phone call.)

Still, Apple fans are left wondering exactly what may come out of this iPhone announcement. At the moment, it's widely expected that Apple will make iOS 5 available to the public and possibly even roll out an all-new iPhone 5, a slightly modified iPhone 4 in the form of the iPhone 4S, or both at the same time.

There's also some talk of a white iPod touch—a relatively minimal detail that reminds us that the fall event was originally about iPods. What will happen to the rest of Apple's iPod lineup? Will it get rolled into Apple's iPhone announcements from here on out? All we know is that the holiday shopping season is looming and Apple is undoubtedly working to get new products on the shelves in time for Creditcardapalooza, and it's only a matter of time before Apple tells us what's up.

As always, Ars will be at the event to cover the announcements live, so stay tuned for October 4.