One single framework which has all features needed.
Too many framework and tools are making life difficult of developers. Atleast for .NET Developers there should be singe framework from microsoft which is sufficient in most of the cases. It should have rich UI controls, support patterns (MVVM / MVC/ DI /Modularity), navigation, unit testing. asyn/parallel WebAPI calls, input validation, security, styling...
Francesco Abbruzzese commented
Several options are better than a single one. Support for the main existing frameworks(at least knockout, Angular, Ember) is better than forcing developers into an unique framework that might be inadequate for some applications. People died for freedom, it is not worth to give it away just to avoid the burden of a choice.
Dipen Lama commented
I see TypeScript a new JS framework from microsoft.