[Adapted from a comment]
There are some early decisions to make that will have a big impact on what directions we take. If we work these through first, we'll can probably save time in the end by not coding solutions that don't fit. A DEP is the process we've set up as a community for working through large proposed changes or new initiatives, and it seems to fit this case.
I've created an issue on drupal.org, http://drupal.org/node/66148 (and also posted to the jQuery list to see if there's a possibility of getting jQuery under GPL.) I propose that we (a) work out the general approach in the DEP post http://groups.drupal.org/node/603over the next week or two, (b) post a draft DEP for the initiative on drupal.org, and then (c) move the actual implementation to http://groups.drupal.org/drupal-js. How does that sound?
Meantime, Konstantin and others, I'm keen to hear some of your ideas and proposed approaches.