I've started migrating my application into the module. The major consideration has been handling the use of LINQ to SQL and the Entity Framework together.
My MVC application uses LINQ to SQL. I had to regenerate the data context with sqlmetal to resolve some odd errors when working with NHibernate. In particular my data context was generated by an old version of sqlmetal – it just needed an updated generation. I found it useful to create a BAT file to regenerate the context for me.
call "C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\Tools\VsDevCmd.bat"
sqlmetal /server:MACHINENAME /database:DBNAME /code:DataContext.cs /language:csharp /views /functions...