OK, so do I or don't I?

I thought XHTML was the right thing to do, but at least one guy who knows what he's talking about is pushing that we stick with HTML 4.01 until all browsers handle XHTML/XML properly without developers resorting to funky tricks.

You're damned if you do, damned if you don't. Go to XHTML and lose visitors who aren't using compliant user agents, or stick with HTML 4.01 and not give people a reason to upgrade?