[cachemoney]

This idea is going into OS X Lion as "Versions"

http://www.apple.com/macosx/lion/

[duskwuff]

I wonder if this'll use a Git backend, like XCode 4 does.

I doubt it'll happen. But a man can dream!

[skeletonjelly]

From memory, this is no different than Microsoft's versioning correct? (Albeit Microsoft's implementation is well hidden. I think I read an article linked here on HN about it).