I still have an old, basic telly. Not found the need for HD yet as, quite frankly, I have yet to see any "Ronseal" HD system. *NONE* do what they claim. I can still see artefacts of compression, stepping, lines, flicker and other problems in HD shows - so why bother forking out £1,500+ for a TV that consumes more power and delivers nothing more than what I have now?
3D will be the same. Narrow angles, headaches etc.
Sound is the key. Get decent sound and you become totally immersed. Where are all the Dolby/THX 5.1 broadcasts; hmm?