Dual and Multiple cores are certainly the way to go. Speeds have hit a wall, going for a Gigahertz advantage simply isn't enough, Intel found that out with the Pentium 4, a pure GHz speed king.
Intel has been the first to market with its Dual Core processor with the Pentium D launching just before the Athlon 64 X2, and this was simply a disaster in terms of performance, heat dissipation and power requirements. The main problem with the Pentium D was the twp cores needed to communicate across the FSB.
Core 2 Quad is another rush job we feel from Intel. While it does perform reasonably well, it's still bottlenecked by the dies having to communicate across the FSB.
Intel has already indicated its next quad core will be four cores sharing 8MB of shared cache, with all cores connected to the same L2 cache module, rather than two cores on one L2 cache and the other two cores on a second L2 cache - this should prove to be a much better design when it comes to performance.
Overall the performance of the Core 2 Quad doesn't justify the price premium that is being put on this CPU. If you are just going for bling value of the four cores, then this is for you, if you want a cheaper alternative, Core 2 Duo with 4MB L2 cache performs pretty damn close to the Core 2 Quad right now.
As a matter of fact, we just got out of a meeting with Valve Software today and they indicated to members of the press that soon they will begin to implement multi-core CPU optimisations into the Source engine which will benefit all previous Source based games and new ones including Episode 2. Initially you will see improvements in frame rates but for Valve, that's just the beginning. They want to leverage the multi-core technology (and we're not just talking about four cores) and improve AI and the overall realism of the games to levels we've never seen before and they seem to be on track for doing it.
From a gaming prospective, is it really worth upgrading to Quad Core right now? Probably not! Is it worth waiting a little while and seeing what all the software and gaming developer companies do? Yes! Right now the hardware is ahead of the software - keep an eye out on patches for your favourite games or applications and decide for yourself if you really need four CPU cores inside your system at the moment.