You can deploy MVC3 to Azure, endure you have all these in the reference and copy local set to true:

• Microsoft.Web.Infrastructure
• System.Web.Helpers
• System.Web.Mvc
• System.Web.Razor
• System.Web.WebPages
• System.Web.WebPages.Deployment
• System.Web.WebPages.Razor

The best way to debug this after a deployment is to have the following in the web.config for debugging purposes:

<system.web>
  <customErrors mode="Off" />
  <compilation debug="true" targetFramework="4.0">

Obviously do not have this for production!

• Windows Azure