I like the idea of replaying commits. Never really thought about it because I tend to look at the current code without really bothering with the way it was developed or follow the commit history anyways if I'm developing myself.

I think the main benefits would actually be in the area of teaching. Just have people that learn to program watch replays of stuff in the language they want to learn and pick up on certain things via patter matching :)

At the very least even pretending to record your commits (rubber duck version) could probably improve your development process quite a bit. I think I'll actually pretend to record all my commits from here on out and give a running commentary to myself :)