Re:Sounds a lot like Vista (Score 1)

There is a blog around somewhere mentioning MS's source control for Vista. Once you make a change, it gets committed to the next level for testing, which then gets merged with other similar project changes, then it goes up to the next level and gets merged with more changes at that level. It was taking up to 6 months to get a change put into the actual current build, which is not a small amount of time if you want to release an OS every couple of years. Imagine, fix one small bug and wait 3 months for it to get to the build. You'd have to think Apple would be a little more nimble than that, but it's still near impossible to fully control a project of that size.