ASP.NET MVC beta upgrade guide for the absent-minded developer.

I've been using ASP.NET MVC since preview 1, and have loved every bit of it.  Between preview releases, none of my code broke -- even between 2 and 3...  Wait that can't be right...

So when the MVC beta dropped recently, I went ahead and upgraded my three projects.  Little did I know that when I was upgrading all of those other times, I was forgetting to update my assembly references!  Big d'oh!  I had been using preview 2 this whole time!

Upgrading from preview 2 to the beta can be a bit of a pain, so here are some hints to make the process easier, if anyone out there actually needs to do this.

• Update your strongly typed ViewData references to use ViewData.Model - This one is pretty self-explanitory.  If you have strongly typed ViewData (by typing ViewData<Foo> in your codebehind) you need to reference ViewData.Model in your views now.
• ViewData is now ViewDataDictionary - If you have custom ViewData-derived classes, you should change them to inherit ViewDataDictionary.  I just got rid of mine completely and created some ViewInfo classes to pack up all the common data I needed to send over that wasn't my model object.
• RenderView("Page") is now return View("Page") - Much, much nicer.  Make sure you change those public voids to public ActionResults as well.  Good work on this change!
  
• Default.aspx has a codebehind page now - If you're getting blank pages, you probably want to update your Default.aspx that is included in the project template.  Just create a new MVC beta project and you should have it ready to copy into your old project.
• Update your Web.config file - There are a few new entries:

In compilation/assemblies: <add assembly="System.Web.Mvc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
In pages/namespaces: <add namespace="System.Web.Mvc.Html" />

Happy coding!