To put the "but what if the user doesn't have SSE2 support?" concern in context, it should only affect Intel users with CPUs older than a Pentium 4 (released 2001), and AMD users with a CPU older than an Opteron or Athlon 64 (both released 2003). All x86/x86_64 CPUs released in the past decade should be able to handle SSE2 binaries, so our caveat can be "if your computer is more than a decade old, 'pip install numpy' may not work for you, but it should do the right thing on newer systems".

 However, from my perspective, having NumPy readily available to users using the python.org Windows installers for Python 3.4 would *significantly* lower the barrier to entry to the Scientific Python stack for new users on relatively modern systems when compared to the 4 current options