The energy efficiency and heat points are valid, but plasmas haven't suffered from significant burn-in or shortened lifespans for years now. I've had a VIERA going for five years and there's no permanent burn-in or any other signs of longevity issues.
The OLED TVs which are appearing right now are definitely the future but they currently suffer from bigger issues with lifespan than plasma ever had, mainly due to the blue parts of the image ageing more quickly than the others — although I believe that LG has very recently figured out a fix to this that hasn't made it into any models yet. Current OLEDs also suffer from burn-in.
That only really leaves plasmas, LCDs, and LED-backlit LCDs (completely different to OLED, basically just LCD); all of which are now obsolete technologies in the face of the move to OLED/AMOLED. (AM(O))LED is without a doubt the direction all screens are going in, but they're prohibitively expensive and teeming with issues right now.
It'd actually probably be cheaper to get a good plasma — or if you really want, LCD — and then replace it in a few years when OLED matures rather than be an early adopter now.