That's a pretty big "if". Unfortunately making python a lot faster is difficult because python is such a dynamic language. The pypy folks have done their best, with a respectable amount of success.
The 10x figure I was quoting was from the comment I was responding to. I do think people need to look at what was accomplished by the Strongtalk team and various other projects dealing with dynamic languages including some Lisp implementations. I'm pretty sure Python can be a lot faster, but the legacy code is going to be a big, big problem.
You missed the but the legacy code is going to be a big, big problem. part. If, as other posters point out, those C extensions are not designed to work without the the GIL, then its going to be a 2->3 situation.
Frankly, I honor the Python folks and all their achievements, but I really dislike the language. I mostly am researching another paradigm.
That's a pretty big "if". Unfortunately making python a lot faster is difficult because python is such a dynamic language. The pypy folks have done their best, with a respectable amount of success.