Office 2007 Developer Roadmap
The Office 2007 system is a truly extensible platform for creating applications. There are some great new features for developers in the latest release.
There are now so many new technologies (ribbon customisations, XML file formats, Outlook form regions, SharePoint workflow support) coming out with this release that it can get difficult to get the bigger picure. To get a feel of that, download the Office 2007 Developer roadmap from here. It shows the breadth of Office development opportunities ranging from the Client and the Server. Its a must read for every Office Developer.
You will also notice that VSTO seems to be supporting a high number of these scenarios for Office 2007.