"Don’t see why you’d want a quad-core, right now, at least for gaming"

Mr. Monett is absolutely correct, the list of games that will take advantage of quad core cpu has grown a lot since this time last year..Even UT3 gets a big boost when using a quad core vs a dual core.

Fire up Supreme Commander on a single, then dual, then quad, and you'll have yourself a clear answer.
Of course, I realize that the vast majority of games have not been in any way programmed for multi-core threading, so the ones that do actually benefit directly from more than one available core are few and far between.
But anyone running a game server (the real one, in a console on a separate box) will bless dual and quad-core CPUs, as will anyone who enjoys any of the few games that really do take advantage of multiple-core systems.