Seriously. The panel technology still sucks right now. I purchased a Panasonic plasma last year on the basis of viewing angles, colour accuracy, motion etc and people telling me that things like image retention were a thing of the past. I avoided LCD because of it's horrible blown whites/crushed blacks, 8 bit panels, clouding, poor motion, input lag, lack of IPS panels and other crap (With LED HDTV's being the most abused term to date - I'm looking at you Samsung - when it's just crappy edglit displays on most sets. You have to pay considerably more if oyu want true local dumming). But even now my Panny suffers from posterisation, phospor lag, motion judder, problems with PAL 50, floating blacks (black goes up and down spontaneously on certain sources) and yes...image retention!
3D is just another marketing scam and people only buy into it because of the rash of crappy 3D movies which are not even freely available on BluRay (Many titles being tied to exclusivity deals on branded HDTV's).
Plus you have expensive shutter glasses to content with (Great if you have kids....not), or polarised glasses which cut down on the amount of resolution of the HDTV and cause lowered brightness levels or you having to pump the brightness up each time you want to watch a 3D source.
Obvious other issues are things like crosstalk.
What we NEED is better panel technology. OLED, QLED, FED or SED (whichever comes first and is most affordable).
3D can go to hell.