If you develop any ASP.NET MVC 3 application (which currently is in RC 2 release) with Razor view engine and you need to run it on Windows Azure then you have to upload some extra DLLs to the cloud. Below is a list of DLLs you need to have as local copies to get ASP.NET MVC 3 run in Windows Azure web role.
You may have noticed that there are some cool helpers in WebMatrix that you may want to use in your current ASP.NET MVC 3 project. The good thing is that you can use them. The only thing you have to do is just download them with NuGet.