Thanks, just watched it. One of the more intriguing of his talks.
From the recent Strange Loop, here is Prof. Sussman's keynote:
http://www.infoq.com/presentations/We-Really-Dont-Know-How-To-Compute
With his trademark erudition and enthusiasm, he talks about models of computation, and about a topic related to the end of section 3.3 in SICP, among other things.