can you control lighting (both ambient and reflected) and are you willing/wanting to watch in near complete darkness all the time?
if so, go projector. something like the jvc x35(this is what I have) can match blacks and apparent contrast with the best plasma's on the market today. but ONLY if you can get the room completely dark. any ambient or reflected lighting will raise black levels, and it doesn't take that much to go from inky plasma black to crappy LCD grey
on the other hand, plasma's have apparently reached their pinnacle of performance. Samsung might be the only one to release a better plasma next year, and it may be difficult to find plasma's in a year or two. projectors are still improving and chances are next years model will be better than this years, and cost less. so it might be an ok time to get a plasma and you can add a projector later.
or, grab yourself a 60" ST60 for daytime/casual viewing, and pair it with a good value projector like a benq 1070, and you can get both for your 3k budget.
Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1130K, 7.1/5.1.2 audio
Sources: HTPC(Enby), PS3, XBOX360, Wii
Control: Harmony One