It's just a dummy for people who might want to flag an addon they got there so they remember to update it, or for people using ancient layouts who might still have that there to prevent errors. I think.
It looks like it just yoinks the versions from the HTML. I'm not sure if this is faster or slower than the XML. I assume the XML are static files, I don't know if the HTML is or isn't. If it's dynamic, it's not necessarily that good. But then, I don't see any reason for the HTML to be dynamic ^^. So it could be better, since all those XML files are larger than the HTML is (at the cost of WUU having to do more work). Of course, I could be completely and totally wrong, it's a pretty complex program.
Looks like a line ending issue. Did you check any mods from here? I don't think it's actually WUU doing it, but the authors saving the files incorrectly. You'd have to ask one of the EoL fanatics around here :P.
I deleted them, then tried again ^^. I gotta be doing something stupid wrong, LOL. I just can't figure out what.
2007-05-16 12:09:21: (WARN) Could not find addon update date on page - is site ID correct?
2007-05-16 12:09:22: (WARN) Could not find addon update date on page - is site ID correct?
2007-05-16 12:09:22: (ERROR) No TOC file for oGlow
I changed them to unknown and tried to update, it "found" zChat, but not oGlow, and it gave me the same error. WoWI is definately up. Argh ><.