A typical example of needlessly wide design is the Amsterdam website; they use the extra space to show a giant e-card picture on each page.
The best option is of course to go liquid. If implemented with enough care, this option would accommodate most screen sizes, and solve most resize issues. This technology is unfortunately still a bridge too far for most webdesign agencies (in The Netherlands).
So what are your ideas on going for 1024? Any recent experiences? Still designing for 800? Got a watertight liquid design methodology? Feel free to share!