Jailbreak Apple TV 3 for XBMC
Although an apple tv 3 jailbreak is not released yet, you can get the advantages of that jailbreak with another device called the Taffy Media Center. One of the biggest reasons to jailbreak an apple tv 3 is to install XBMC.
XBMC is an award-winning free and open source (GPL) software media player and entertainment hub for digital media. The features of XBMC are endless and with plugins, the feature list is growing everyday. Taffy Media Center is a linux based box that boots directly to XBMC!
Faster Interface and 1080p Output!
The two other big reasons for jailbreaking an apple tv 3 is for 1080p video output and faster speed while using XBMC. The Taffy Media Center already can output to 1080p and is much faster than a jailbroken apple tv 2.
Plugins . . . Plugins . . . Plugins . . .
The jailbroken apple tv and jailbroken apple tv 2 are both very compatible with the plugins for XBMC. This is very valuable as the plugins for XBMC allow you to easily stream free video content from many sites across the internet with a simple remote control. Android TV boxes with XBMC are having many issues with these plugins as XBMC for android is still in development. The Taffy Media Center is based off of XBMC Linux which is fully developed and is just as compatible if not more so than a jailbroken apple tv 2.