There is no source code out for Android 2.2 yet to my knowledge. Since CM is derived from the source well you will have to wait a little while longer.
Only people with 2.2 right now are N1 users and Droid users who flashed to the leaked Froyo build. The release on the N1 isn't final code yet either. You will probably see another OTA in the future once the source has been released.