If you haven't had a chance yet to see these great videos that Kathleen has made of VSTO in action, check them out.  They're each about 6 minutes long are are really nice glimpses into some of the cool features of VSTO 2005.  Keep 'em coming Kathleen!

Demo 1 – Locate and Delete NamedRange Controls

Demo 2 - Resize Controls Within Worksheet Cells

Demo 3 - Add a Custom User Control to your Document

Demo 4 - How Column and Row Order is Persisted in a Data-bound List Object