So, as we narrowed down the possibilities, let me try it once more, with speculations going full steam ahead.
So, as Roslyn has a scripting API, with fully dynamic REPL support, maybe we will see a Roslyn based client-side web development environment, provides Edit&Refresh dev experience, using C#/VB or C#Script(csx)/VBScript(vbx) as the development language, MSIL2JS as compiler backend, TypeProvider-like dynamic integration of data sources and Web API, Razor-like HTML mixing, etc. Now the question is, does it support XAML ?????
So, Steve Lucco for the runtime (Chakra), Erik Meijer for the bridge (MSIL2JS), Anders for the language and tooling (Roslyn), three pillars of something ?