Like most users, I'm finding the switch from Office 2003 to Office 2007 to be relatively painless, EXCEPT, I've been consistently experiencing a delay when switching between instances of Word.  It finally annoyed me enough to research the issue, and I located the solution here...the culprit turns out to be the Acrobat PDFMaker COM Add-In.

Note that this post is not SD-related, directly, except that waiting on Word to switch windows cuts into one's development time.  =)