Soon enough the 64-bit world will be upon us. I hope that it isn’t as much of a hassle as moving to 32-bit (although my guess is that it will be).
Craig McMurtry (MS Blogger) has a real quick series of 64-bit related articles. This does an overview of the hardware available and software that MS provides (or will provide). Short, excellent articles to get you up to speed.
64-Bit Windows Part 1
64-bit Windows Part 2
64-bit Windows Part 3: The Itanium Processor
64-bit Windows Part 4: The x64 Standard
64-bit Windows Part 5: A Summary Comparison of the Two Species of 64-bit Processors
64-Bit Windows Part 6: The Hardware Landscape
64-Bit Windows Part 7: Taking it Personally - Michael Dell, are you reading this?
64-Bit Windows Part 8: What is Microsoft doing about 64-bit personal computers
64-bit Windows Part 9: Microsoft Operating Systems
Also, if you ever find yourself actually using Windows 64, this article gives some handy tips for using it.
First Post - all things x64