After a million+ downloads on the PC-only side and development for years being always done solely by Mark Overmars, Gamemaker is finally coming to the Mac!
http://glog.yoyogames.com/?p=15
It’s a superb package for learning game programming and I for one am lined up to replace my PC copy with a Mac version.
Finally!
PS. This is a great tool to use to introduce 2D game programming.