We are just beginning to reap the benefits of JavaScript everywhere. On the (web) client, on the server ( node.js ), on the database ( e.g. MongoDB ), even my editor of choice ( Sublime Text 2 ) stores its config files in JSON format, and it can run at stonkingly fast C++ like speeds thanks to V8 under the hood of Chrome and powering node.

I would take a lot of convincing to move away from JavaScript at the moment. The suspicion is that Microsoft just wants to control things and is threatened by this convergence .