I have put together a quick reference on are the default Work Item Type (WIT) each TFS version. This is very handy when you need are doing a upgrade to a new TFS version and need to know what template type you have.
TFS 2010
Scrum Templates have the following as a base
Product backlog item
Bug
Task
Sprint
Impediment
Test case
Shared step
Agile Templates have the following as a base
User Story
Product Planning Workbook
Task
Bug
Issue
Test Case
Iteration Backlog
CMMI Templates have the following as a base
Requirement
Change Request
Task
Bug
Issue
Risk
Review
Test Case
Resource links for TFS 2010 WIT
http://msdn.microsoft.com/en-US/library/vstudio/ff731587(v=vs.100).aspx
http://msdn.microsoft.com/en-us/library/ms400752(v=vs.100).aspx
Resource links for TFS 2013
Work with team project artifacts, choose a process template
Work item field reference for Visual Studio ALM
This is a quick reference to WIT. This is a large topic on its own. By having a common understanding of how the WIT are different from each there, it makes the upgrade process much easier.
