Supposedly, it makes the Nexus One run 450% faster, has Flash support, supports tethering and mobile hotspot, allows you to download apps to the sd card, etc...
Of course it's available for the N1 first. I may wait until the update to possibly update to the HTC Evo 4g. I really want that HUGE screen but if they can get the N1 to run better, I may save my money.
http://www.washingtonpost.com/wp-dyn...052003295.html