Scott Guthrie announced at MIX 11 an update to the ASP.NET MVC 3. See detail here.
You can get the update using Web Platform Installer, or download and install it directly.
You don’t have to uninstall Microsoft ASP.NET MVC 3 - Visual Studio Tools. The installation does take a while (more than a few minutes) to complete.
I actually canceled the process initially. After rebooting the machine I started it all over again and finished it successfully. So be patient!