Along with developers building applications exclusively for Visio, there are a lot of people who do development across Office (or are thinking about it). The Office MSDN team has done a great job putting together a poster that gives you a sense of what type of development is possible and how Visio fits in. For me, one of the key messages on this poster (and something that we'll be talking about going forward) is the increased importance of Visual Studio Tools for Office (VSTO) as a way to develop Visio solutions.

Poster Image

The poster will be given out at events like TechEd, but you can also click on the poster image to download and print.