1. For most applications, the JS MVC framework needs server-side backing, so don't fool yourself: You are no longer using MVC- you are using MVC X 2. There is no magic server-side out there that runs on self-generated jellybeans and weed that will power these frameworks. They are beautiful but unnecessary cruft in such pretty packaging that you think they are doing you a favor and washing your clothes for you. But they are only washing part of your clothes. The rest are still dirty and on the floor.
2. Despite the old saying, "Everything at some point will be written in JavaScript," it is not JavaScript, but rather mobile application development that is leading the charge in the development world currently. It is the platform and the accessibility (intuitive, easily held and portable), and not the "how" (whether it is webkit running Ember or Angular).
So, even though it is awesome that Ember and Angular are great, and I'm happy for you Yahuda, just like I'm happy for Misko/Igor/Vojta, I think this is a lot about only part of a solution, and it might not even be the right one. The whole package and the platform must be considered, not just the web client UI.
So, I ask, now that v1.0 is out, what is being done about considering the ease of developing the entire shebang?