I found that when converting a project, I had to manually change the csproj file for the web application. It needs one additional projecttypeguid to show the mvc stuff when you do add new item.

 Below is the corrected version:

 <ProjectTypeGuids>{603c0e0b-db56-11dc-be95-000d561079b0};{349c5851-65df-11da-9384-00065b846f21};{fae04ec0-301f-11d3-bf4b-00c04f79efbc}</ProjectTypeGuids>
  

Are you converting from an earlier MVC project to make use of MVC via the Preview 2 release and this is occurring?

Yes, I have an MVC project from the first CTP and I upgraded it by following the release notes. When I tried to add any mvc object like a mvc form, they did not show up in the add dialog. Once I added the additional project type guid, I got a submenu of mvc under web and everything is happy.

You converted it correctly.  Adding the MVC project guid is necessary when moving from the CTP to Preview 2..

 Thanks, this also solved the problem for me - I just spent an hour comparing project and configuration files but didn't spot that it could be this.

Update: it'd be great if someone updated the readme for preview 2 to include this instruction.