I don't think the technology for 3D has changed much at all since the 50's. The reason they never used it for feature length filming (if they did they kept it limited to short stretches), is precisely why Fizz doesn't like it - it gives people a massive headache and even nausea after about 20-40mins.
This latest lot is digital mastered so the media's 'cleaner' but when you take your glasses off the picture's still a double image so presumably they still use the slightly different camera angles which the dark glasses 'merge' for you to give you illusion of it being 3D - how the hell they can do it for TV I have no idea unless it's something to do with the screens I suppose?
All I can say having seen Avatar and Alice (yesterday) in 3D is that Avatar at 160 mins + was well worth the headache despite the over-simplified plot (in my head it's got depth though - loads of motifs and symbology in that, which would make a far better book although I don't how competent an author James Cameron is but then the screenplay is hardly complex...

).
Alice was marvellous visually, but I thought it didn't really
need the 3D and it didn't seem to be that noticeable because of the rest of the CGI which was spot on in nearly every case. The subject matter's surreal and 'impossible' to start with so it doesn't need to rely on the gimmicky side of things so much although someone we know went with a 4 year old who was totally entranced with the more obvious 3D element and kept screaming for everyone to watch out so she had the entire daytime audience in stitches
