Thanks for you comment, Sumit; I think that’s a very good idea that you outlined.

I had already been thinking of implementing Drupal’s commenting system with Ajax, but this could certainly be applied to Drupal’s blocks as well. With keep-alive HTTP connections, it should not have a very detrimental effect on the server, either. Certain types of blocks, like shoutboxes, are in fact anyway better-suited for asynchronous use in the first place.

However, I’m not yet sure how much less of a strain it would be to render a Drupal block, instead of a whole, themed Drupal page. Since blocks can make use of full Drupal functionality, I think Drupal might need to be fully bootstrapped in order to serve out even just a simple dynamic block, such as the Quotes on this site. But this certainly merits some experiments.

Congrats on getting accepted to Google’s Summer of Code! I had a look on your blog, and GData is definitely something I’ll need to read up on. May your endeavor be successful!