The Guardian has an interesting overview which covers many frequently asked questions relating to 3D TV's: You can read the article here.
Great primer article on 3DTV. To continue on from the last point about 3D TV being a gimmick, I think that it's the perception out there that 3D is a replacement and I don't see it that way at all. In fact, I think some things simply won't look good in 3D.