Well, it looks like the fuss over Vista's EULA, mentioned in my previous blog, has been unfounded. Microsoft has changed the license in response to demand from enthusiasts and will now allow the license to be transferred to a new platform an unlimited number of times. The license now reads, "You may uninstall the software and install it on another device for your use. You may not do so to share this license between devices." Obviously you'll still need multiple copies if you want to run the OS on multiple computers, but that's certainly a fair deal.
However, this revision only seems to apply to hard retail copies of the OS. It may be a simple oversight, but for now it appears that if you choose to download Vista using the new "upgrade anytime" feature instead of purchasing a hard copy, the license can only be transferred once (see 15b in the EULA). Fortunately I don't think that will be a significant issue for most enthusiasts, as most will want to have the actual install disk in hand.
Personally, like many people I don't want to mess with trying to "upgrade" XP, which can be buggy and problematic. I'm going to purchase a new high-speed hard drive and do a clean install of Vista.