First, let me apologize for the missing table of contents and index on the Professional Team Foundation Server 2012 page. I think having at least the TOC handy would help and when I started to answer your question I saw those missing and have asked someone to add them. I've also gone ahead and attached the table of contents here as it might help answer some of what you need.
So there are a couple of issues to deal with:
The parts of this that have to do with Visual Studio functions that aren't in Visual Studio Professional and require VS Ultimate or VS Test Professional, those limits will still apply:
But, as far as TFS goes, you can connect a ton of different IDEs to it - it supports old versions of VS, it supports Eclipse.