I stumbled across this over the weekend.
I was actually very surprised by how closely it resembles what we've been working on at the office. Ours uses a controller to manage and control events and event propogation, track "view objects" (we call 'em "client controls" for drag-and-drop support in Visual Web Developer) and manage AJAX calls. And we've spec'd out to use RESTful URIs to manage data model retrieval and callbacks, and these are cacheable using Google Gears, Flash storage, or *shrug* cookies.
Theirs has a few additional features, though, some of which I think we can glean from, like:
script librarian ("Include"), which we don't need but I think we could accomplish using something like JSLoader
a complete ActiveRecord-like modeling pattern
a complete ASP-like templating system that executes on the client
"everything is a plug-in" philosophy
In some ways, ours is looking like http://www.wavemaker.com/, except that WaveMaker is based on Java and dojo, and the designer experience is in-page (which is way too much support overhead--why reinvent the designer when Visual Studio / Expression Web can do the job on its own?).