There are 3D>2D glasses available on Amazon cheap, and they are not an April Fools joke. They are custom made with 2 left lenses which cancel out the 3D effect. Look up "2D glasses" on Amazon and you will find them. I imagine they are great for when somebody goes with friends to see a 3D film, since they can see 2D without having to see the 2D version all by themselves while their friends see it in 3D.
Myself, I've always loved 3D. It doesn't bother my eyes in the slightest, even with red/blue anaglyph glasses, as long as the 3D is done competently. That is the key. And I wear regular glasses too. The polarized 3D in the Imax and RealD theatres nowadays can be amazing if the director knows what he is doing with the 3D. I've seen several newer 3D films - Avatar, My Bloody Valentine, Up, Saw - most of them were awesome but Saw was terrible because it was too dark all through the film and not filmed at all well with 3D in mind. You don't need to constantly throw things out of the screen at the audience to have good 3D - while that can be fun for certain films like My Bloody Valentine, good 3D can just mean using sets and cameras to make the most of the 3D technology. Film with 3D in mind. Even in the 50's there were great polarized 3D films made, like House of Wax just for an example.
On the other hand, I feel some 3D films today are a bit too restrained. House of wax had fantastic depth that really pulled you into the film, as though you were really there, without constantly tossing things out at you. Some 3D films today have such a restrained use of 3D that it doesn't even feel 3D, which just disappoints the audience. The trick is finding a balance of 3D techniques that work together to immerse you in the film. Just because you have a 3D camera doesn't mean you can film good in 3D. I used to take stereoscopic pictures for a hobby, and just because you point a 3D camera out the window doesn't mean you're going to get a great 3D picture. You need to compose your shot. Same thing with movies.
I'm usually dead against 2d>3D conversions because they are usually crap. I will admit that I've seen Piranha 3D and it looked really fantastic in 3D, and that was a conversion. I honestly don't think I would have known that it was a conversion just by watching it. The filmmakers said they took their time with the conversion and wanted to get it right, and I think it shows. They filmed it knowing ahead of time that they would convert it to 3D in post, so they filmed as though they were actually filming in 3D. I still think filming in true 3D is the way to go, but I'll be curious to see what James Cameron does with Titanic next year. He knows what he's doing.
As far as Star Wars, that's another thing altogether. Even if the 3D looks great (I have my doubts because the company he chose, out of several different 3D companies, is the one who did the conversion for Clash of the Titans which was atrocious), it will most likely still be blue and will most definitely still be the special editions. Plus I hated the prequels so I have zero interest in seeing them again, 3D or not. The only ones I might be interested in slightly is the OT, but it will be years before those are out.
One thing I'm getting really sick of is all the animated G-rated kid's flicks. Who can possibly afford to see them all even if they wanted too? Over-saturation. These things are a dime-a-dozen now and they're getting old quick. They all look the same and studies show that kids have a hard time sitting still with the 3D glasses on anyways, and tend to keep taking them off.