who knows if we will get it officially, but once the source code and all is released when google officially releases the final version of 2.2, chances are the guys over at sdx will get it working on our phones
i personally say try the leaked 2.1...its awesome so its worth it in my opinion..but there are downsides like the batterylife and a couple other little tweaks you gotta do afterwards to get things like streaming fixed
You can always go back to stock
start here... READ THIS FIRST! SDX Android 2.1 - All the Release Info
then here... Android DD10 System Update Released
Then here for root... [How To] - Root Android 2.1 DD03/DD10 - v7