I'm looking for a tool that will generate an assembly/project dependency diagram in Visio (or as close as possible) to assist me with breaking up some of our system into more manageable trunks.
The ability to include/exclude non-project dependencies is a must (i.e. include/exclude System. assemblies).
Try ReSharper. (I'm not associated with the product or company, but it provides many nice features for dependency walking).
You can also try the Depends.exe with the SysInternal toolset - now from Microsoft.