At least with tfs 2013 you do have the ability to work disconnected with local workspaces. Distributed vs centralized is defined by the business and depends on the needs and requirements of the projects under development.
For enterprise projects the ability to connect workflow and documents to code changes can be critical in connecting business requirements and higher order elements to specific code changes that address a specific change, bug or feature addition.
This connection between workflow and code repository separates TFS from code repository only solutions. For some places where a higher order of project auditing is required only a product like TFS would satisfy more of the project auditing requirements.
An overview of the application lifecycle management process can be found here.
http://msdn.microsoft.com/en-us/library/vstudio/fda2bad5(v=vs.110).aspx
