Nope.  I hadn't clicked on them.  I assumed that the template writer knew what they were doing   As to whether or not its important to follow them, I would say yes.  In a lot of causes that will cause some browsers *cough* IE *cough* to not render the page correctly, but at the end of the day, standards are all you have.

So, interesting story.  My company recently got bought by a much much much bigger company whose intranet is one of the 7 wonders of the world.  A fair number of pages on that site - mostly web applications - won't work in IE.  Quite a change from the company I was with that got bought who would break anything end everything else to support IE.

There's a difference between supporting new features that aren't called out in the standard and improperly implementing a standard, the way MS does.  If you do any amount of web programming, you know that you have to make exceptions for IE.