I just got one a few weeks ago. Order AVIA if you havent. Turn the PICTURE setting down to about thirty first thing. Also go to www.panny.tv for advice, lots of cool stuff there.
Also, what other equipment and cabling do you have? You want to be able to take advantage of that new TV dont you?
I would suggest a Progressive scan DVD player and a good set of component cables for it to really show off stuff.
Do you have access to HDTV content? Do you have an XBOX? That system is actually really good to show off a TV.