I'm just a hobbyist at this point, and I don't know how much trouble/cost this involves, or if it's ever done, but I would love to have a source control system up on Winhost. My application and database are up there on the server (obviously), so the source control is the only part of the 'production' process still sitting on my local computer. Other than that, I've got everything I need!
At this point, this isn't something that we are actively looking at. But we are keeping a list of stuff that we may do in the future.