I don't think this is practical.
Parsers for scripting languages (and optimizing their execution) are an extremely specialist and time consuming area. I don't know much about it. Also given that the selection routines for conditions are very complex, I think the auto-generated code would be extremely ugly and difficult to work with, which would defeat the point. It'd probably be slower, too - we'd never have time to write an optimizing compiler-to-assembly, so it could never compete with the compiled code in the runtime at the moment.
Integrated Python snippets (when it works), on the other hand, are already fast, flexible, and can perform the algorithmic things that events aren't so suitable for.
In short, I think this is one of those "wouldn't it be amazing if..." ideas, which in reality, would be cumbersome, not as useful as people imagine, and a huge drain on developer's time.