Downloaded and installed fine for me on my Droid running LithiumMod. dancedroid
Is this only for rooted phones?
I'd agree with that. The Nexus 1 CM ROMs hit first, and Koush ports the code to the Droid, and at least one person has reported that the N1 build worked on his droid for a while before it lagged out and he replaced it with the Droid ROM.CM6 RC's seem to have something (probably in the build.prop) that allows for users to see adobe flash in the market. My guess is they have faked the market to believe you are running the N1 instead of a froyo droid.