To Python-level code, Python's threading model is pretty much exactly the same as that supported in all "fast" languages such as C and Java (even Go, ever pragmatic, has locks). Given that Jython already allows true multithreading and PyPy is trying to emulate it with STM, it's reasonable to see the GIL more as an implementation bug that won't be fixed for practical reasons than as a threading model... even if Python also supports alternate threading models that are perhaps better for most applications anyway (if strictly less powerful).
> To Python-level code, Python's threading model is pretty much exactly the same as that supported in all "fast" languages such as C and Java
Yes, but Python also exposes higher-level operations like table manipulation as language primitives.
> Given that Jython already allows true multithreading
That may be, but as I mentioned this has an inherent cost, both in CPU and in memory. Therefore it is not a strict improvement over CPython, just a different direction.
