Workflows of MSF Agile and CMMI Process Templates for TFS
When trying to decide which of the two MSF Process Templates - Agile vs. CMMI Process Improvement - for TFS is the right starting point for your company, it helps to compare the work item types and its workflows.
You can download the full guidance from:
MSF for Agile Software Development
featuring 5 work item types: Bug, Requirement, Quality of Service Requirement (QoS), Risk and Task.
Work Item Type: Bug
Work Item Type: Scenario
Work Item Type: Quality of Service Requirement (also known as "technical requirement")

Work Item Type: Risk

Work Item Type: Task
MSF for CMMI Process Improvement
featuring 7 work item types: Bug, Requirement, Change Request, Issue, Review, Risk, Task
Work Item Type: Bug
Work Item Type: Requirement
Work Item Type: Change Request
Work Item Type: Issue
Work Item Type: Review
Work Item Type: Risk
Work Item Type: Task
As a personal note:
Both templates are a great starting point. The agile template might be a bit more lightweight whereas the CMMI template might fit more the vocabulary and processes that you are used to.
However, both are really just a starting point. In customizing the process you get way more out of TFS than with just using the built-in process templates.