One more entry on this very busy day: the VSTO team announced today that VSTO will be (has been, but it's still in beta) expanded to include support for creating Outlook add-ins with managed code. There's a 5-page description on MSDN already.
This is making a cool tool, VSTO, even cooler. If you haven't noticed VSTO yet, it's time that you did. My Office 2003 category is pretty much all VSTO posts, versions 2003 and 2005.