Office Business Applications (OBAs) are an emerging class of business applications connecting line-of-business systems with the people that use them through various Microsoft Office applications. OBAs enable businesses to improve adoption of their LOB systems, minimize end-user training costs, and increase end-user and business application developer productivity. I believe that over the next several years OBAs will profoundly change the way poeple approach business application development.
Ed Hild's blog is a great source of information on OBA development techniques. Ed is a Technical Architect at the Microsoft Technology Center in Reston, VA and an expert in Office-based solutions. He is currently finishing a book focused on Office 2007 development due to be published later this spring. Take a quick look. I think you will not be disapointed.