Attempts at client side rendering? What attempts are there (successful or otherwise), to move the heavy work in templating to client side javascript?
If I understand your question, the only projects that I am aware of are 


jQuery Mobile (I am pretty sure this is abandoned)
Backbone
Node.js


There is a related discussion in Using Javascript frameworks like Backbone with Drupal and some of the work for Spark could probably count, too.

I don't have direct experience with any of these, but I am in the early process of determining whether Backbone is a good fit for a particular project.