>I don't like the idea of working with multi-languages HTML, CSS , javascript, some sort of middle like python, perl, and a web server. ... So if javascript is going to be the language for the near future then why not use it for all the layers. Node eliminates web server, backbone provides the model, and enyo the UI.

Exactly why I started to follow node about 2.5 years ago and pointed that stuff out here about 2 years ago...
JS is IMO not as nice/clean as Python, but a common language in all layers trumps that - again IMO.