NumPy is making pretty strong headway in many communities. It's still not Matlabby enough for the majority, though. It doesn't make a clear improvement, so I think many see it it as just poorly replicating the features of Matlab for free.
It's also pretty notoriously difficult to install, especially if you want LAPACK/BLAS. I wasn't able to get it running on many of our servers for that reason and had to revert to Matlab.
