I've done about fifty interviews now for the Code Generation Network and none of them has been as cool as my talk with Sergey Dmitriev about what he is doing with his Meta Programming System (MPS). With this thing you can quickly define a syntax, an editor and a code generator for an arbitrarily complex Domain Specific Language.
I didn't get to see it in action during the interview but we got together a couple of days later to show it to me and I was blown away. Even in it's rough form it shows great potential for creating a new higher level of abstraction in programming beyond Object Oriented, and beyond Code Generation, that Sergey is calling Language Oriented Programming.
Extremely cool stuff. I am very excited.