I had a solution where I was building a WinRT compoent dll. I updated the Windows 8 version to Consumer Preview(from Developer Preview) and updated the Visual Studio Ultimate Beta version. Now the solution cannot load the WinRT component dll project. Also, trying to create a a new WinRT component dll gives the following error:
http://picpaste.com/Screen_Shot_2012-03-13_at_11.25.06_AM-X6Pc0MLI.png
You will need to create a new empty project file and manually copy the source files over. The project files are formatted and organized differently. There is no conversion routine that is officially supported.