Have you been hearing all the hype about the new 64-bit CPUs and OSes. Are you confused about what this means for you? This article gives you a brief introduction to the technology. Although the article doesn't answer compatibility questions, about: software, drivers, and hardware.
Here is an excerpt from the article: "Though 64-bit computing has been around for some 14 years or so, until recently it has been accessible only to those operating high-end servers running RISC-based processors such as Sun Microsystem Inc.'s SPARC, IBM's Power and Hewlett-Packard Co.'s PA-RISC."