Visual Studio 2012 is now available to MSDN subscribers:
Visual Studio 2012 splash screen
I don’t see any changes in default Visual Studio tabs behavior comparing to Release Candidate, but they slightly changed packages registration and I had to update the Tabs Studio installer. With the update, Tabs Studio is now compatible with VS 2012 RTM as well:
Tabs Studio in Visual Studio 2012 RTM
Download link: Tabs Studio v2.8.1.
Tabs Studio Blog (organizing Visual Studio document tabs) 
Where is CloseLeft Tabs addin?
Comment by Sergio — January 15, 2013 @ 1:53 pm