If you've noticed references to HTML 5 or XHTML 2 pop up around the web and aren't aware of the differences between the two, then be sure to read "HTML5, XHTML2, and the Future of the Web" over at Digital Web Magazine.

The article lays out the pros and cons and the general arguments for each language. As you'll read, there's quite a lot in the pipe as far as updates to the functionality of forms, basic client-side APIs and the structure of markup.

Some additional reading:

The future of HTML, Part 1: WHATWG

The future of HTML, Part 2: XHTML 2.0