Oh i know what you mean now, I have that on my SGS what i gave to my GF...
From what i know its only a CM9 / AOKP feature, They are compiled and built different than Sense ROMs..
Who knows what clever devs could do, But at the moment it doesnt exist... But in my opinion, I dont like it. I guess its cool on the nexus because as you said it has no hardware buttons, but on a phone that does, Its quite confusing.
Thanks for the congrats
im loving it, Just development is soooooooo slow, I dont think ive ever been on a stock ROM for so long.