I am looking at the latest catalogues of Panasonic and Sharp and it is quite apparent that across the board, the power consumption of a Plasma is still significantly higher compared to an equivalent sized LCD. Not surprising at all because both camps are taking energy conservation seriously, hence while one camp has successfully improved their power ratings, the other camp is actually achieving the same.
However according to Panasonic, they have reduced the power consumption of their newer models by at least 30% compared to their own previous models (of the same plasma panel resolution). BUT, that does not apply to their latest full HD plasmas which are comparatively power hogs.
On the other hand, perhaps power consumption is the least of concerns for those who can afford to buy large-sized panels.
When commercial establishments, airports, museums, convention centers, etc. started using large panels (I dont remember how many years back but probably during the late 90s), plasma was the only practical solution at that time, and for most commercial applications, there is not much practical reason (yet) to change their existing facilities to LCDs right now, unless perhaps Sharp or Sony donate their large LCDs.