I'd like to second the request for a very detailed blog post written by one of the PyPy devs on how interested parties can contribute to the development of Numpy on PyPy. Lack of Numpy support is the showstopper for me and a lot of other people in terms of switching over -- almost everybody who wants faster Python is using Numpy in some way or another :-) This is something I would be really interested in working on.
Not really, numpy depends too much on cpython internals. There is an interest in rewriting numpy for pypy, but I am not sure whether this is the best way of doing it. From what I understand, the choice is between better pypy's compatibility with C extensions (easier, but slower because of cpython emulation in pypy) vs rewriting it for pypy (harder, but would benefit more from pypy).
