Count me as someone who thinks 3D films can be neato and occasional gimmicky fun, but they're only something I'd want to see every now and then. In other words, a fun visual show when you're in the mood for that kind of thing, but mostly a bad way to see a movie.
I liked Coraline in 3D, and thought that it was ok for the new Tron movie (didn't think the movie was very good, but the 3D was an ok fit), but mostly it'll make me less, not more, likely to see a movie.
I have a slightly different reaction. It's not so much that I think 3D is a bad way to see a movie (though the glasses are annoying for those of us who have to wear them over real glasses), but more that I think it brings nothing to the table.
Here's the thing: there seem to be two basic types of 3D movies. The first is the kind that ostentatiously yells 3D! at you over and over. You know what I'm talking about: spears tossed toward the audience, monsters suddenly looming out of the background, etc. If you like that kind of thing, fine. But I just find it ridiculous and distracting.
Then there are all the others, the movies that basically do 3D right. It's a natural, unforced part of the visual experience, and perfectly enjoyable. Except that when it's that natural, I don't even notice it after the first few minutes. My brain — and yours, I imagine — does such a good job of perceiving 3D in a 2D movie that there's very little difference in the two experiences. Except for the annoying glasses, of course.
I saw a bunch of 3D movies around the time Avatar came out, and then I just stopped. There was no point. I don't hate it or anything, I just don't really get anything from it. So why bother paying?
(But you know what rocks? Closed captioning for the hearing impaired. I accidentally went to a couple of shows with captions a few months ago, and it was great. I actually caught all of the dialog, even the parts that were barely whispered against a background of machine gun fire. I won't pay for 3D anymore, but I'd be all in favor of some technology that placed invisible captioning on all movies that could be made visible with special glasses.)