[b]--Updated 1/28/2010--[/b] Unfortunately Adobe Flash will not be supported in Couch Surfer Pro when running AppleTV 3.0 or later.
The AppleTV 3.0+ software includes a highly customized version of Webkit. WebKit is used for many system functions including media playback, cover art display, searching and of course web browsing. Unlike previous versions, this version has disabled Netscape type plugins such as Adobe Flash, Quicktime and Silverlight. We spent many hours attempting to recreate a new version of WebKit that would allow for enabling these plugins while retaining the normal functionality of the AppleTV.
After 3 months, and an enormous amount of research, development, and testing all attempts to create a new modified version of WebKit resulted in lost features and system instability. It's apparent at this point that due to the highly customized nature of the AppleTV that creating a set of WebKit frameworks that will support Adobe Flash while maintaining a normal operating system is next to impossible.
We'll continue to research alternatives to enabling Adobe Flash and will post any updates here.
Note: Adobe Flash can be viewed in Firefox after enabling Flash as described here: http://support.firecore.com/entries/259320
[b][Update 3/8/10][/b] Even with Adobe Flash properly enabled, Flash video performance in Firefox may still be less than ideal due to the AppleTV's limited processing power.