http://jarrodmillman.blogspot.com/2009/01/when-will-numpy-and-scipy-migrate-to.html
Python 2.6 by March 2009
Python 3.0 by mid-to-late 2010?
Once Numpy and Scipy hit 3.0, we can port NeuroTools: this shouldn't be a very difficult task, since NeuroTools is pure Python, with no C-extensions. Porting PyNN depends on the simulator backends - NEURON, NEST, PCSIM, Brian - being ported, but again, PyNN itself should be a straightforward task.