The benchmark you're referring to is very misleading indeed. The PS tools, filters, and core app eat megahertz for breakfast. One cpu does not scale differently than another when it's the same architecture. Additionally when PS goes 64-bit in a few more months all of these benchmarks can be safely filed in the dust bin.
Well I hope we don't see a new PS in a few months, I just bought CS4! The earliest you will see CS5 is around March-April 2010, latest around November 2010 if they stick to their usual product cycle (18-24 months).