This seems to be a new feature in SQL 2012 ‘Denali’ RC0.
The following blog post has more information. Seems quite interesting. They also have a sandbox where you can play around with it,
but this site has been down for the last two days.
Update – More demos available in the sandbox now. Check out : http://blogs.msdn.com/b/oneclickbi/archive/2011/12/27/more-demos-of-power-view-available.aspx
Currently still seems to be a number of bugs especially with some charts etc. I am unable to find a connect program to submit the bugs though as yet.