Here is a Panorama Control that Pivots.  It’s up and available on Codeplex for download..

http://phone.codeplex.com/

There is another community based control also available from Clarity Consulting..

http://blogs.claritycon.com/blogs/design/archive/2010/03/30/building-the-elusive-windows-phone-panorama-control.aspx

Source Code Available HERE

Here is a video which describes what this looks like..