Currently it is not possible via version control, mostly because I didn't want to rely on a user having the required version control application installed on their machine to install a package. I don't think it would be a terrible idea to add a setting that would allow users to "prefer" to use git or hg for grabbing plugins from GitHub or BitBucket if they have it installed. If you open an issue at https://github.com/wbond/sublime_package_control/issues
I bet we could work out a way that would be really user friendly.
And yeah, I figured after hacking some SFTP functionality for a while that I'd try my hand at making a little money off of it. I've done quite a bit of open source work, but this is my first foray into the commercial world.
ST2 is awesome that it exposes so much for plugins. I enjoyed figuring out all of the different ways that it is possible to hook in to the program.