Exciting to explore the new and improved features with the release of SharePoint 2013 Preview. However, one thing that I noticed after installing on a test machine is that you no longer see the option to sign in as a different user. This “Sign in as Different User” menu item is very useful when testing applications. Seems like the link purposefully removed from the UI. Is it still under review by Microsoft as this is a preview version or will still be carried over to the final release also. A little comparison with a SP2010 environment shows that the actual link for signing in as a different user is
Fortunately this link still works in the Preview version of SharePoint 2013. So far so good. But is there a way to add the link back to Preview version? The steps to add the link back are mentioned by Nick Grattan in his blog post.
Hope this helps!