Last week I spend three full days submerged in Office 2007 development while attending the 2007 Touchdown training for ISV's in Melbourne. The first day was entirely dedicated to VSTO and the XML file formats. Now that VSTO SE is available you can actually do some really interesting stuff in Word, Excel, Outlook etc.
Eric Carter, one of the authors of the Visual Studio Tools for Office book I highly recommend has posted some interesting examples on his bLog. The last one particularly interesting as one of the students in the room with me last week was looking for info on how to display Item Context menus.
Note the following remark on Eric's bLog:
"Also, a small comment on VSTO Second Edition. Some have assumed that VSTO second edition is a super set of VSTO 2005 as the name kind of implies. This is not the case. You will want to have both VSTO and VSTO second edition installed at the same time in most cases. VSTO has the document projects for Word 2003 and Excel 2003. VSTO SE adds application add-ins to target Office 2003 and Office 2007. The two products should be installed together to get both document and application level customizations."
I'll try to bLog about some Sharepoint dev experiences next week, I have been experimenting with generating documents containing sharepoint list data automatically using event handlers and that seems to be a really cool way of using Sharepoint for data collection (using Infopath) and reporting.