That's interesting. I felt some of the fight scenes were a bit messy too and took it as the fault of the editing (like Batman Begins), but it'd be something if they had filmed it for 3D assuming certain stuff would pop or sink, and thus would be easier for the eyes to discern.Watched it with my two oldest yesterday, this time in 2D.
I found that a few scenes were/felt more chaotic than they were in 3D - mostly the fighting scenes. Not bad enough to warrant annoyance at all - it was fine in 2D.
I expect I'll be buying it when it comes out on blu-ray.
Crap, now I'm curious about seeing it in 3D.