Just for the fun, here are your quad core games coming down the pike. Some are already here:
http://www.alanwake.com/
http://www.supremecommander.com/
http://en.wikipedia.org/wiki/Half-Life_2:_Episode_Two
http://www.unrealtechnology.com/
http://www.splintercell.com/
Patch to be released for this:
http://www.microsoft.com/games/flightsimulatorX/
An article about quad:
http://techgage.com/article/intel_core_2_quad_q6600/7
They also say Crysis will use quads, but I have yet to see anything that shows a perf improvement over duals yet.
The short of it though, Quad will be a necessity going into 2009 so I wouldn't want to be caught without it if it were my only gaming system and I were upgrading right now, and I knew I wasn't going to upgrade it for 2 years or more.
Just my 2 cents as always.
-S