Team Foundation Server 2008 allows that every check-in is associated with a work item, but what do you do if you are developing some features which span several Team Projects?

For example, you're developing a specific product for a client and that product has its own Team Project, but is also using some of your other components or tools which are maintained independently in another Team Project.

Where do you create work items for requirements which involve a change in both projects?

1. Separated, every work item in its own Team Projects
2. All work items in clients Team Project, regardless of associated source code

The latter seems easier to maintain and control, but it involves associating check-ins from one Team Project to work items in another.