W3Schools: Browser Statistics
Browser trends is important information. What we you can read from the statistics here, is that Internet Explorer 6 is the dominating browser, XP is the most popular operating system, and most users are using a display with 800x600 pixels or more, with a color depth of at least 65K colors.

800x600? Who are these people? are they partially blind too?

What's more important to the designer is the size of the browser screen the users tend to use, not their screen resolution.