Robert Cooper - Why I Hate Microformats:

"Yay, you have an iCal microformat in your page. You can use Trails, now to stick it right into your Google calendar. Neat.

The problem is, this is a serious abuse of HTML. The way you SHOULD have done this is:

    <html:div xmlns="http://www.w3.org/2002/12/cal/">
       <vevent>
       <dtstart>20060501</dtstart><html:abbr>May 1</html:abbr>
    ...

Then present your iCal entry with CSS. Yes, we have waited years and years and years for Microsoft to get off their rears and implement CSS with namespaces, which everyone else has had for years. However, IE7 is around the proverbial corner, and we should finally get the option to embed actual real data into our HTML pages and style it. There is no reason to use semantically incorrect HTML and beat up on the class attribute."