Via Andrew Hinton's memekitchen a great article by Zeldman in Digital Web Magazine. "99.9% of Websites are Obsolete."
Often, non-standards-compliant sites work in yesterday's browsers because their owners have invested in costly publishing tools that accommodate browser differences by generating multiple, non-standard versions tuned to the biases of specific browsers and platforms. This practice taxes the dial-up user's patience by wasting bandwidth on code forking, deeply nested tables, spacer pixels and other image hacks, and outdated or invalid tags and attributes.
More good food for thought for next quarter's web design students.