Thought I would link to it, the idea is so nummy. Generating C# assemblies for XNA on the 360 would be a fun trick to master. The RPG Kit for XNA is pretty nifty as a starting point. Perhaps in the same way that TorqueX 2D works on top of XNA, though with more built-in functionality and less coding, of course...but with C# rather than Ruby for the code junkies out there experienced with the RPG Maker realm.
I do not know how many times I have heard the worlds "RPG Maker is too limited for my vision" or some semblance of that sentiment around game development communities. While it does indeed fuel spur-of-the-moment engine license purchases, it also houses a much larger problem: project ineptitude. I do not think that I have seen a finished (or even alpha) project from anyone who has made this claim in any engine. It could definitely be because RPG's are hard to make. Yes, this is true, but even if you have the right tools, could you make it?