Lampooning Marvel's celebrity roles and cameos as well as inter-film continuity seems a bit strange considering that most of the films were as well received as we've seen; even though the goal seems to be illustrating how absolutely horrid a Hollywood treatment of Nintendo characters would be (and I'm sure there would have to be a few reboots before anyone "got it right," certainly), I'm unashamed to say that if the end product were anywhere near as well done and high quality as Marvel's offerings (setting aside 3D, which I'm not entirely sure is just a fad anymore and damn I hope it is), I'd probably give it a chance.
That said, Thor shows just how difficult a tightrope it is to balance realism and fantasy in film when the source material is almost wholly fictional; Marvel characters at least occupy a world (that's intended to seem) much like our own, whereas Nintendo characters occupy a whole other universe entirely. It would be very, very difficult to get away with Hyrule, or Popstar, to say nothing of Mushroom Kingdom.
The production costs of the Iron Man series are astronomical, and it's supposed to be happening in America's backyard; I can't imagine what the costs of creating entire virtual worlds would be, except to hazard a guess that the CG Beowulf film would probably be a fair comparison.