Team System: Check-In Changes To Multiple Projects in a Single Changeset?

Question

We have a Team System environment where our applications are set-up as separate Team Projects. Often, we run into a scenario where a development task requires updates to code in multiple Team Projects.

In this scenario, what are the pros/cons to having a single changeset that contains coding changes across multiple Team Projects? What are the pros/cons to using a one-changeset-per-Team-Project approach?