If you go in and ask most TV salespersons they'll tell you that the market is heading towards LCD. Not that LCD is better than plasma it's just the way the market has swung (beta vs vhs). Two years ago both had equal amount of showroom space, now there are less plasmas displayed.
I heard more problems with plasmas and a higher cost for repair.
I've read just the opposite.
I've been researching these sets for quite awhile because I'm in need of a new one and what I've come across is that if you're going for under 45", then get an LCD, anything bigger, go with plasma.