just to point out.
the games were run WITHOUT AA on purpose, on high end gear, to show the theoretical difference between framerates on different cores.
even without AA, you CAN NOT SEE, and no one cares about 190fps on a dual core 3Ghz compared to 160fps on a quad core 2.4Ghz. this is again on an engine that uses one core, at a later date the engine is being updated to use multiple cores which should put the quad core ahead in this specific benchmark, but either way, multiple, quad core, single thread, they will all perform the same when 4-8xaa is enabled. they will become gpu limited and say all give a fps of 100 on any cpu setup.
quad core is faster than the dual core in basically everything except a few benchmarks to show the theoretical power of the cpu on very specific single threaded games/encoding apps. add full AA that you would infact use with a 8800 or any other top end card and all games would perform the same.
utterly no need to get a quad core for gaming, at all right now. until games add advanced physics that will really need more cores to run and will disable extra bits there will be no need. but game makers rarely put in anything significant that won't run on average kit thats been around for 1-2 years. like ageia and some pitiful effects that can't be shown and make entirely no difference to the game.
now power wise, a penryn on smaller process that uses a buttload less power and in theory will overclock further and be cooler, with added SSE4 is the quad core to go for tbh.
the only reason theres any discussion at all about getting a Q6600 is because, frankly £160ish is just plain insane for that amount of juice, even if you won't use the extra power, we all like a great deal. now the other thing is, a Q6600 is so cheap that if you got one now, then sold it to get a penryn or phenom then well, the value won't be dropping massively any time soon so you wouldn't lose much getting one and selling it on in a few months.
one thing to look at is "marketing" hype words and that is all games that state quad core/multi core compatibility are.
even in the most massive of game setups in supreme commanded a quad core offers a very small increase over dual core. games don't separate a single game engine over multiple cores. game makers have split up there engine into being able to process say physics, ai, graphical info, dx info, drivers into separate threads and push them across cores. the problem is the main threads can't be split up further. so physics is one core, ai is one core, and no matter how far you spread everything else sound will never use much power, so while you can put more and more threads on other cores the main threads are stuck to one core only. we will not for a long time see 2 cores 100% faster than a single core, and a quad core 100% faster than a dual core.
its why to a point, a single/dual core with higher speed can be better, but only when you set the game to lower detail levels to show those differences basically. every game that showed significant speed differences did so without using highest detail levels.