We are now working on MVC 6 which combines MVC, Web API and Web Pages into a unified Web framework. You can find the project on GitHub at https://github.com/aspnet/Mvc and https://github.com/aspnet/Razor.
We are tracking issues for future versions of MVC 5.X, Web API 2.X and Web Pages 3.X in the Issue Tracker here. The work for MVC 6 is tracked only on GitHub.