Well, it's not 2010.2 anymore because I had to upgrade a few packages ;-), but if you want to try out some of the new GHC 7 features this can get you a working cabal-install. Download here:
http://parfunk.blogspot.com/2010/10/hacking-together-working-version-of.html
Apologies if this is already available somewhere, but I didn't see it.
Cheers,
-Ryan