Not really. Two cores is probably the most the game will use. There is a little benefit as the OS operations can run on another core. However, when RAM is accessed by any core, it essentially stops the other cores from accessing the RAM, so you might inadvertently increase stutters in the game using 4 cores, versus 2.
Most people do not understand only one CPU/core can access RAM at a time, whether it is being read or written.
The reason video programs benefit from more cores is the data packets they work with is small enough to fit into the cache of each core during transcoding which allows all cores to work at the same time. When data is too large to be held in the cache of any given core, the performance drops dramatically.
In some applications, 4 cores is no better than 2 cores.
The i7's are a videographers dream come true. In a standard transcoding benchmark, my 3.7GHz E8400 took 2 minutes 46 seconds to run the test. An i7 system ran it in 56 seconds. Yes, I want one!
