Hiya
there are 2 types of 3D glasses that are needed for the latest generation of 3D capable displays. One is the expensive 'active' type which 'electronically' control inbuilt shutters (or equivalent) to create the effect of 3D to the wearer. Then there's the 'passive' much cheaper type, much like the method used over the last 40-50 years each time 3D has been tried for the masses.
I have interest in a different area of Consumer electronics and so only know a limited amount in terms of the technology, however as many aspects of the electronics and film studios and media companies are involved now so heavily, 3D is likely to stay this time around. I first saw the latest generation 3D stuff at the CES show in January 2010 and I was left a bit underwhelmed. Yes, the effect is there, however it depends on the content itself and 'how much' is done for 3D that is important. If you like your older content then expect 'parts' of the films/shows etc to be -remastered for 3D content. It was a demo of something out of Indiana Jones I think I watched, the scene where the mine carts turn into a roller coaster - only 'some' of the content was in vivid 3D. However, something modern and 'made' in 3D from the outset will knock your socks off !
Is it worth investing? only you can decide with more research - look over on avforums.com for the real indepth discussion !
I also saw 3D capable projectors, and played a video racing game demo and was impressed with that to an extent, I saw some other demo's which had the wow factor as well.
What really blew me away was the demo of 3D displays that didn't need any eyewear at all! and all I can say is WOW and double WOW! however that technology is at least 3-5 years+ away yet, they could only show this early prototype on a screen about 22 inches in size, but the effect was there and vivid - I kept walking side to side, closer and further and ducking and trying to raise up to check the visual - it was fantastic!
For me personally, I'm not investing in 3D just yet, perhaps in a couple of years - for others like you mention, with kids, I'd do some more research from now until Xmas, go check a few places out that stock them, do some demo's and wait for the boxing day sales to kick in!
Cheers, DtM! West London & Slough UK!