Rumor has it that Apple is planning on changing the name of the Apple TV back to iTV which will still only support a mediocre 720p.
The hardware will run on iOS 4.x and be powered by Apple's A4 processor, which is the reason for only supporting 720p video at best.
The iTV device will be able to download apps from the App store but there has been no word if apps will be specifically made for it or primarily intended for the iPhone/iPad.