If you keep up with the latest processor and hardware technologies you know that 64-bit is the next big thing. For more than 15 years 32-bit has been the architecture of choice for almost all computers and devices, but as the limitations (in particular in the area of RAM) begin to be more apparent, the move to 64-bit becomes more and more important.
One of the problems facing Microsoft is the slow adoption rates of x64 Windows XP and Vista. If you listen to Security Now!, you may have heard of the important security features that x64 Windows brings to the table, and essentially restructuring Windows during this transition. While some people seem to disagree with me, 64-bit Windows just doesn’t seem to be compatible enough for most users, most often running into hardware issues or just plain incompatible software, despite the fact that 32-bit apps are supposed to run just fine in the 64-bit environment.
On the Mac side, things are a bit different. Not necessarily better, but definitely different, and it will be interesting to see how things play out in 2009, as it is suspected that next year will be that of 64-bit Apps (Notably Adobe CS4, and potentially some “legacy” Carbon-coded Apple applications like Final Cut).
AppleInsider has an excellent series on the history, present, and future of 64-bit, that, while focussed primarily on the Mac platform, has an excellent overview of the Windows perspective. Check it out, it’s an excellent read.