I think a lot of people are missing the point with this movie. Tony Stark isn't in his suit a lot of time for 2 reasons.
1) It highlights how dangerous the real "manderin" really was as a villain because he was able to completely crush Tony for most of the movie (parallels Bane's role in DKR actually). It shows that Tony is highly vulnerable and mortal.
2) Tony without his suit is representative of the journey he goes on throughout the movie to find himself again. Back to basics, so to speak (as seen when he has to rebuild his suit; cope without Pepper; hang out with the kid who he sees a bit of himself in; etc).
I thought all of these things were a nice departure for the series and will transition him nicely to the role that IronMan was usually in in the comics (making and using technology for the benefit of other superheroes rather than fighting). I also enjoyed how they brought back the comedy that the second movie lacked. Obviously I still think the 1st move is by far the best, but this movie has a lot to appreciate (despite the kinda stereotypical creation of a bad guy...dude gets blown off at a Y2K party