Pandas + Statsmodels for linear regression / GLM / Discrete Choice, ARMA / ARIMA, and various non-parametric ops.

For GIS: Fiona (Python OGR operations); Shapely for geometric object manipulation, analysis, and set-theoretic operations; RasterIO (self-explanatory); Descartes and/or Basemap for drawing; PySAL for spatial analysis.

GeoPandas (an unholy, massively useful combination of most of the above) is also under heavy development.