Probably. Not only will the native 64-bit coding speed up day to day use, but we also have two other great improvements coming in Snow Leopard that will be sure to speed up your Mac. The implementation of Grand Central Dispatch and OpenCL will help to utilize every ounce of power that your Mac has. If 10.6 were to include only one of these great advancements, we probably wouldn’t notice a difference, but with all three working together you can be sure that OS X 10.6 will feel faster under your fingers then OS X 10.5.