Let's keep this in perspective.
Even the beloved CRT RPTV's will get burn-in. Go over to that forum and do a search, you'll find alot of threads concerning burn-in.
IMHO, if anyone is to be using a display device and most of their viewing is 4:3 content then I would suggest not even considering a 16:9 display, unless of course it is a FP. Phosphors are phosphors and as long as display devices have phosphors they will age differently if they all aren't being used for the same duration. Ergo, you get burn-in.
For our habits a plasma is perfect as it is unobtrusive and we watch alot of varied programming.
FWIW, Jugdish I do not agree with many of your statements and as usual, it all depends on the end user. Further, burn-in will not "ruin" the screen, it may ruin the viewing pleasure though.
Pssst, I don't think LCD has "as good a picture" as plasma, and so far my absolute worse investment was in a little company called "Mack Trucks". That cost me a fair amount of $$$. FYI, I am about as "real" as a person can get.
Just my .02