Your statement that NumPy is "nowhere near the speed of C" is false and misleading. For some people "NumPy" is actually just a front-end to the vendor-optimized libraries that actually do the work (and your C-coded loops are going to be much slower than those). For most operations (with large-enough vectors) NumPy is only 2x slower than a specific crafted C-loop.
Yes, there are generic operations in NumPy that you can speed -up with specific code in C (or any-other compiled language). In addition, there is much low-hanging fruit to optimize in NumPy as well (which we at Continuum are working on as I write this).
Fijal, I know you are enthusiastic about PyPy and you should be --- it's a cool system. But, please don't spread mis-information. There are a lot of people who don't understand enough about the details of what you are talking about, and you are just going to alienate them once they realize that you don't have all your facts about NumPy clear.
For people who only make occasional use of NumPy, PyPy and it's version of numpy will likely be fine. But, those people should be well-aware that they are intentionally remaining outside the larger Python/NumPy ecosystem (Matplotlib, SciPy, scikits, etc.) and it will be a long-haul to build the features in PyPy to enable that ecosystem to migrate (and that assumes the individual projects decide that it's even worthwhile to do so).
Fijal, I'm not sure you even understand my perspective. None of your comments in response have given me confidence that you do. I have no disagreement with you about how far "PyPy could go". Obviously, we could re-create the entire Python ecosystem including the scientific stack under its run-time. I just question your understanding of how expensive and time-consuming that would be. My official position is that I think it's possible to get the benefits of PyPy (i.e. fast Python loops) in different ways that don't also toss out years of extension modules in the process and whose answer to current users about the features they rely on in CPython not working under PyPy is "just port it" or "just use ctypes".