Remember the days of the Athlon 64 and its promise of high performance using 64-bit technology? It's a good thing the Internet existed then, and we had enough information at hand to at least know that the 64-bit thing was not going to do us any favors. But the CPU was still pretty fast, and we bought it anyway.
The amazing part of the story is that 5 years later, and 64-bit adoption is still on its infancy.
Adobe recently said that it expects to begin taking full advantage of 64-bit processing in the next version of Photoshop CS4, which will be a Windows exclusive due to recent underlying changes made in OS X that would have pushed back their plans. Adobe preliminary tests showed visible performance improvements on this 64-bit version, but only when the program is pushed to certain extremes, for example, opening huge 3.2 gigapixel file on a system with a lot of memory, then you could expect up to ten times the speed compared to 32-bit just because you don't have to rely on the hard drive as much. But for the average Photoshop user, the improvements should be more in the range of 8 to 12 percent, the company said.