Sorreltiger:A friendly salesman in John Lewis encouraged me and my youngest to try out a Sony 3D set-up. IMO the 3D made the movie picture much darker and not nearly as sharp - even though the 3D effect worked quite well. Football was HORRIBLE - desperately difficult to follow! However, youngest was REALLY taken with the gaming demo and I can see that this could be the break-through area. I had to admit that this looked great too, although not too loudly as youngest was starting to get ideas!
Should have looked at the Panasonic, the picture in my demo was fantastic if not entirely perfect (occassionally could detect a little flicker).
Also, any demo is subject to how the tv is set up and has been said on here many times before, what looks best / worst in the shop doesn't necessarily look the same at home away from all those bright fluorscent lights when properly adjusted. My advice is view demos at several stores or independants so you can get a better feel for he picture or better still find a shop that calibrates their demo screens.
As for 3D, I was very very impressed by the Panasonic but personally wouldn't buy one quite yet. I'd rather wait for the take off than buy something expensive and have it go obsolete even if it can still be used for 2D.