Tommy has been asked the famous Ten questions by the WSG. Although I don’t necessarily agree a 100% with all of what Tommy says (for instance, about the benefits of, or lack of, using XHTML), he’s full of knowledge and it is a very good read.
Regarding coding semantically correct and using a strict doctype, be it HTML or XHTML, we’re definitely on the same page.
But when it comes to using the ABBR or the ACRONYM element for abbreviations, I think the discussion about different layers of presentation is far more important.
Personally, I use the ACRONYM element because I want the IE users to able to see it as well.
All in all, I recommend reading the interview.