I came in late and it was hard for me to hear and understand everything, but this was one of the coolest talks.
This is Python written in Python running in a virtual machine. They had runtime modifiable grammar working; they added "do while" on the fly! They have proxies that claim to be actual instances of another class; they showed a demo where a "list" was actually proxying to a database. Somehow they showed a demo where they were embedding a shell in a browser; they were using emacs in the shell in the browser to play emacs' Tetris! I think they have a "@lazy" function decorator for lazy evaluation. They've created new technology in their JIT. Their funding runs out in March, so that will slow them down. They support multiple backends, including LLVM. Extension modules are problematic for them. They're thinking of multiple frontend languages.
Hmm, if they're moving toward multiple frontend languages, and they already support runtime modifiable syntax. It sounds like they'll have a working version of Perl 6 ;)