Out of a bunch of cool presentation at least week's San Francisco Ruby meetup, my favorite was Choon Keat's demo of a working implementation of his hquey project -- a lib that lets you use Ruby, CSS, and jQuery patterns to bind data to views ... in the DOM, on the server side.
He had previously blogged about the motivation -- the core idea is that 10-15 years into the web application era, we are largely using template languages for integrating data into HTML. We've come a long way toward avoiding procedural code in our templates, enforcing MVC, etc. But aside from collectively agreeing to avoid a set of 'worst practices,' we're still inserting data into HTML in a manner reminiscent of 1998.
For well designed pages, with CSS classes and/or IDs, it should be possible to specify the data binding using CSS on the server, without any special binding tokens or markup. hquery does just that. So a designer can create full mockups with dummy data, and hquery can swap in the live data
The current demos and syntax might be touch verbose, but this is just an intial proof-of-concept and Ruby lends itself to easy re-arrangement an API if you need to.
This sort of radical division of dynamic data from HTML, while still using standards and not introducing yet-another-meta-templating-scheme reminds me a little of the old idea of using XML+XSLT to create pages. We all know how popular that ended up.
The hquery approach seems about fifty times more accessible to the present community of developers ... so the question is: how do we make this more popular and build community interest?