Tapulous' Tap Tap Revenge 2 [App Store] seems to be the first application (to our knowledge) to be posted to the App Store with support for push notifications. The new feature only works under the iPhone 3.0 software and allows players to invite their friends to a game. Additionally, MacRumors reports that Apple has posted the iPhone 3.0 software to its servers for the iPhone 3G S. It's unlikely that the software will work on anything but the 3G S, and may not even load on a 3G. We recommend against trying this on anything but an iPhone 3G S.
All sorts of fun things have been discovered in the days since the iPhone 3.0 beta was released, and the fun continues today. Boy Genius Report has posted a screenshot (image below) which shows an option for "Find My iPhone," a feature which has yet to be announced. Engadget has also stumbled across a screen (image below) which suggests that video recording will be included in a future iPhone hardware revision.
Since its announcement yesterday, there's been quite a bit of speculation about what new features iPhone 3.0 will bring. BoyGeniusReport claims to have some concrete info which points to MMS and USB and Bluetooth tethering as two features which will definitely be included in the new software. MacRumors believes that we'll see background processes in iPhone 3.0, which we've previously reported.
At WWDC, Apple announced that they would be providing developers with a "push notification" service, allowing them to notify users of new data without having to keep said app running. The solution would be a perfect fit for twitter, instant message, and other such applications. It was supposed to be available last September, although we haven't heard anything on the service since its announcement. According to MacRumors, Apple may be considering background processes after all.
According to MacRumors, the recent iPhone 2.x firmware has evidence of the next generation iPhone. Found in a property list inside the update image (USBDeviceConfiguration.plist), the suspected new iPhone is designated "iPhone2,1" while the current iPhone is "iPhone1,2."
Jason O'Grady at ZDNet has picked up on an interesting rumor here at Macworld. According to him, Apple is currently working on a four-core iPhone running OS X iPhone 3.0. The 3.0 software is said to be required on the iPhone "quad."