Perhaps, according to Cinematical:
With 3D films being seen as a license to print money, it's not at all surprising that Marvel would be pondering when to jump on the bandwagon. Rumors abounded that Iron Man would be converted into 3D, to accompany a 3D Iron Man 2. Those proved to be unfounded, though Kevin Feige admitted to Heat Vision that they thought about it, but ran out of time in post production. "We couldn't have turned over a version of the movie 10 or 20 weeks earlier for 3-D conversion without undermining the quality," he said. "We used all the time we had for mixing and editing and discovering the right tone." (Seeing the quick-and-dirty 3D Clash of the Titans may have helped that decision too!)
If Marvel is going to do 3D, they want to do 3D right. "The team has been doing a lot of research into 3-D processes, and we're looking at it on future films when we have the time," Feige said. "We will be doing it at some point." That point may be Thor (which wasn't shot on 3D cameras and would have to be converted in post), but it's far more likely to be The First Avenger: Captain America. That begins shooting this summer in England, giving them ample time to use 3D cameras and all kinds of technological wizardry. It would also be a pretty ideal character to debut 3D with -- Cap is, after all, known for throwing that indestructible shield of his. He also slams people around a lot. It's the ideal prop for 3D, moreso than Mjolnir. (That's my humble opinion, of course.)
Of course, to those who really don't care for 3D, this will come as a bitter disappointment. If there's one thing the Marvel Universe might not need, it's more bells and whistles. Then again, the possibility of seeing Iron Man do 3D pelvic thrusts is an awfully tempting one.
-I trust Marvel to not do conversion, but we'll see...thoughts?