The original Apple TV appliance ran a custom version of Mac OS X on an Intel processor, while the latest $99 version is now an iOS device built around Apple's ARM-based A4 chip.
This necessitates adapted support for playback of iTunes LPs, which add liner notes, lyrics, photos and other graphics to digital music albums, and iTunes Extras, which augment digital movie downloads with DVD-style special features such as behind the scenes footage, deleted scenes, and other bonus content.
While the new content first appeared in iTunes for desktop playback only, it contained code references to "HDTV" features that suggested it was targeted at Apple TV playback. Within a few weeks, Apple released Apple TV 3.0 software with support for iTunes LP and Extras.
The work required to add support for iTunes LPs and Extras to the new iOS-based Apple TV will likely also be reused to bring it to iPad, which uses the same 1024x768 native resolution as iTunes LP and Extra content. iPhone and iPod touch users may also see content playback support added for iTunes LPs and Extras.
Apple is currently in the final stages of preparing iOS 4.2, which brings AirPlay wireless audio, video, and photo streaming to its entire range of mobile devices. An update for Apple TV is also expected, along with an updated release of iTunes 10 and Mac OS X on the desktop.