Then I discovered sammy.js, which provides a nice approach to routing and linking. my current project uses that, and i roll my own data access code & use EJS for templating. I also have written all my own glue.
The space is calling out for a "Javascript on Rails" that takes a variety of different libraries and combines them in a canonical way so that each new project doesn't have to go through a shopping expedition, deciding which libraries are currently the best.
What's needed, basically:
1. Routing, navigation + back-button. Single-page JS apps operate very differently from normal apps because many links are hash links, eg. #settings. Sammy.js handles this nicely.
2. models. Here I have a different definition of what a model is than Backbone. I see a model as a class that wraps a particular service. So you might have a TwitterModel, YouTubeModel, MyServiceModel, etc. They would all benefit from inheriting from a base class that does the necessary networking (JSONP, JSON, etc.). It would be nice if all data came back from the service in the form of a Backbone.js Collection.
3. Views. There is a lot of code that ends up being needed around rendering templates. Think of the variety of different render() functions that exist in rails. That translates to Javascript, in my experience. Rendering templates into a div, doing pre- and post- processing, even swapping rendered blocks into invisible divs so they can be swapped back in quickly when the user hits the back button.
I could go on about the neat things that could/should be done, including all the declarative programming and "convention over configuration" stuff that rails does (example: render_foo() loads template foo.ejs and renders it into <div id='foo'>)
Anyway I feel myself a bit lost in a sea of googling whenever I try to find the definitive projects in this space - so I hope some will comment with their fave MVC-esque projects for Javascript...