The people leading the XML revolution have done great work. XML is one of those standards that will work, assuming we get over that pesky installed base problem (there aren't, as of yet, any appreciable number of users, tools, or data). I've swallowed the XML koolaid and use the stuff intensively.

But, let's hold on before we declare this the official paradigm for the next millenium. Reducing congestion on Internet backbones? Sure, if the whole world had efficiently tagged all data and no other protocols or plugins sit inside of the data, we might, in theory have smaller documents. But, and here's the rub: people use software. With XML, we're making our servers do more (hence they become less efficient), we're giving users the opportunity to pump lots more data onto the net (hence the network is used more intensively).

And, that 404 error message? Give me a break. XML will not make webmasters more clueful. Clueful webmasters are not one of those things you can standardize at the W3C. Please pardon my heresy, but this protocol may slice and dice, but it ain't a digital Ginsu knife.