My blog has now been changed to http://blogs.technet.com/mfugatt This site will continue to exist but all new postings will be made to my new blog.
A new article has just been posted by Eric Hartmann over at the Exchange Team blog that discusses how the OWA Free/Busy Posting Process works.
Everyone else has blogged about it, so I thought I would as well, Microsoft has made the XBox Theme for OWA 2003 available to the public.
So it appears that SP2 for Windows XP breaks a few things in OWA, most seem to be caused due to the popup blocker in SP2: http://support.microsoft.com/default.aspx?scid=kb;en-us;883575