Uh, it's not just a question of older PCs using the lower resolution. I've had the option to increase my resolution for years and years. My wife, however, likes the lower resolution because she dislikes the tiny text of the higher resolution. The trend of increasing the default resolution of websites isn't really a technology related question, it's a taste related one (at least in my case). I agree that some basic web design principles, like not making the page scroll sideways for lower resolution screens, should have been applied.
Also, it's spiffy and all that, but it's too spiffy. It's too graphically and flash intensive for me to feel very comfortable browsing at work, and I won't have as much time to do so at home (plus my resolution is lower, as stated above) so for all intents and purposes, the new website is now useless to me.