C# or Python. Python IF you have other products that can use it, like Maya, simply because it will pay off in more ways then one. I'll be learning Python myself soon so that I can start adding some custom tools to Blender. I just put it off because I'm doing too many things at once, and the Blender Python API will be…
yeah, I was caught in the giant fat windows 7 UI style whirlwind, sue me ;) I am planning to redo the whole thing whenever I get more than 2 weeks of python behind me and migrate the remaining MEL into a full python script. For a while I wanted to do that distance threshold option, but as the script is laid out right now…
ya blender uses python, which is a very clean and very good scripting language, that will also be useful to you if you move on to modo or maya since both of these also use python for scripting. also really $150 is a big deal for you, when investing in tools to do your work?
I'm pretty pumped about further python integration. We do tons of PyQt stand alone and it's always a pain to have to go back to doing UI in mel. They've also announced pyMel in 2011, which is huge! If you're not on the python train, time to get on board. Choo Choo!
Comtypes is a good alternative I find to the win32 one which can be buggy, I have had great success controling Photoshop with maya's python interpreter this way. Actually if you look in my SIG at the psLink video that was all done with the openmaya api and comtypes with maya's built in python.