Yep. PVP gear works fine for PVE in a pinch. In rare cases a PVP piece is best in slot for a particular spec.
To the OP: less QQ, more Pew Pew. PVP gear isn't causing you any headaches, bad players are, and bad players will always be there.
---------- Post added 2012-01-18 at 03:26 PM ----------
If you pay your $15/month, you have every right to be in that raid/dungeon. Get over yourself. PVP gear doesn't make someone perform badly.