Asynchronous filters would be helpful for ASP.NET MVC (WebAPI already has them).
Copied from: https://aspnet.codeplex.com/workitem/9582
Comments: +10000 This is a must to have. at some point in ASP.NET MVC, backwards compatibility shouldn't be a concern and controller pipeline needs to be cleaned up. Honestly, if I have the nice Razor compilation (as it's now in ASP.NET MVC under IIS) on ASP.NET Web API, I would use Web API for the web applications, too cuz the pipeline is semantically right there.
Copied from: https://aspnet.codeplex.com/workitem/9582
Comments: +10000 This is a must to have. at some point in ASP.NET MVC, backwards compatibility shouldn't be a concern and controller pipeline needs to be cleaned up. Honestly, if I have the nice Razor compilation (as it's now in ASP.NET MVC under IIS) on ASP.NET Web API, I would use Web API for the web applications, too cuz the pipeline is semantically right there.