I do know how limiting Game-maker is, but is it possible to have Mine-imator load plugins like Bukkit?
It would be interesting to see what features users would add to the program, like a block from a Minecraft mod, or a plugin that adds audio.
People could write model converters to convert different .object files from different places to support Mine-imator, and then import them on demand.
Of course, this would require an API to be written, and that's what I'm worried Game-maker might limit.
it would be a cool feature that I'd want to get creative with. =P