If it's possible to transfer mods from a computer to a 360 (which, I know it is) and someone were to make another online co-op mod (like, or hopefully better than the last), wouldn't that make a type of two player mode accessable on Live?
Player made mods will not be downloadable by the Xbox360. It's possible if one is really good the Devs might decide to take the time to make it downloadable but I doubt it. I'm actually more worried I won't get the downloadable content released for the Xbox because I'm PC.
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A man once asked the Buddha, "How does one escape the heat of the summer sun?"
And the Buddha replied, "Why not try crawling into the blazing furnace?"