Recently I've noticed that after installation VS 2012 I have 2.0 version of "ASP.NET Web Pages" assemblies like System.Web.WebPages.dll, System.Web.Razor.dll, System.Web.Helpers.dll etc. Since I remember there was version 1.0. This cause a lot of problems when I'm deploying web application to production server because there I have only 1.0 version and csproj file contains a references to . So in Dev visual studio has a reference pointing to C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v2.0\Assemblies\System.Web.Helpers.dll which does not exist in PROD.
QUESTION: Nevertheless I’m wondering what cause the upgrade of "ASP.NET Web Pages" assemblies? Is it because of async support in .NET 4.5 or is there any other reason?