Apparently the full version has some support for DirectX so 3D graphics are now possible. Not sure how viable that really is knowing that Game Maker can have some performance issues when you really load it down (or at least it did in older versions apparently). I'm not sure what other changes there may be, though that's the most obvious one from earlier versions. Still though, my planned project isn't super ambitious on a technical level so it should serve me well.
I should probably mention as well that a couple of friends of mine (one being my best friend who I was collaborating with on previous game development endeavours that were far more ambition than we had the time or ability to pull off) is working on a browser based 10-player Bomberman style game. Apparently it's coming along quite well so far and he's hoping to start play testing it with the 3 of us to start out sometime in the relatively near future. He asked me to make some music tracks for it too so I need to dig out my small MIDI keyboard sometime soon so I can get going on that.