You pay more at the movies for it too. Just been told it's about £14!. It's a "special" thing, so it costs more. And it's an option, not a must. If ya don't want it, just buy the normal one. I'll go with a 3D option any day over 2D when it comes to some movies.
I Think the £15 price point for 3D is probibly my limit. I don't have a 3d tv at the moment but it's future proofing as its inevitable that I will have one and from what I have seen the 3D on tvs is very good. Would much rather buy it on blu ray so I can watch as much as I want then pay the rediculous prices at cinemas now.