Team Foundation Server (TFS) is the fully integrated solution to manage projects, giving developers, testers and management a single source of truth for all project needs.
TFS's integration with code/SQL/SharePoint which provides a dashboard with project reports, giving them greater visibility of the project status and burn down lists
The easily customization of the data using Excel Web Services
TFS 2010 for the SQL and SharePoint Server Explorer and the integration of viewing, creating and deploying
That they don't have to try to interpret a bug report from a tester, and then they have to reproduce it. Why? Because of Intellitrace, which allows you to double click and open to the exact line of code with the variables set.
Seamless source control
No waiting for compiling and tests to run. The integration with the build server (continuous integration) is the biggest productivity boost you can give a developer
SharePoint Wiki
The many ways of automating their manual tests via:
The fact they never have to spend time reproducing a bug before documenting it
And it gets better, they don't have to document it because testing tools recorded what they did
Later on, when they decide to go with Lab Manager they will never spend time setting up that special environment (say running windows 95 and IE6)