Minor correction. The removal of the GIL is not disallowed by fiat.
To piggyback: don't forget that CPython ≠ Python. The GIL is an implementation detail of CPython, not a feature of the language. Other Pythons -- Jython, for one -- have no GIL.
BTW, if you'd like to chat more about concurrency, I'm around all weekend (although I'm late getting to the University of Belgrano today). As my comments during your talk yesterday indicated, I think you're pretty off-base arguing that people aren't trying out interesting concurrency solutions in Python — ZODB is a (somewhat broken) STM that's been production-stable for many years, and Stackless is specifically targeted at actor-based modeling.
So I think people in the Python community have actually been way out in front on these issues. It's just that most people use Python for production work, not research, so the researchy stuff doesn't make it into the mainline.
To piggyback: don't forget that CPython ≠ Python. The GIL is an implementation detail of CPython, not a feature of the language. Other Pythons -- Jython, for one -- have no GIL.