For those who were using Visual Studio 2005/2008 it would be confusing too see the Editions on Visual Studio 2010.
Visual Studio 2010 comes in mainly 3 editions
Visual Stduio 2010 – Ultimate ( Similar to Team Suite in VS2005/2008), has all the full functionality.
Visual Studio 2010 – Premium ( Similar to VS2005/2008 Team Editions)
Visual studio 2010 – Professional ( Similar to VS2005/2008 Professional / Standard )
apart from the above, we have a Visual Studio 2010- Express Edition, a free version targetting certain specific development.
I thought of putting in a simple diagram explains you, How the editions differ from Visual Studio 2005/2008 and Visual Studio 2010. Left side has the editions in Visual Studio 2005/2008 editions and right side has the matching edition for Visual Studio 2010.