I can see how this would be useful but it is practically impossible to write something that will work for everyone. A lot of people use a hosted server and can't execute a batch file. And there are others that would be pretty nervous about running a batch file that can potentially be malicious, since it would have elevated permissions.

I feel I have automated the install and upgrade process about as far as I can given the various constraints.

If you come up with something I encourage you to share it, but I won't be working on one.

Having said all this, I will soon be working on getting GSP into Microsoft's Web Application Gallery, which will provide a streamlined installation process. Not sure what they have for upgrades, but they might have something slick there, too.