I think they should be asking "How do I do X" before choosing a version to install. The answer might lead them towards IronPython or Jython, not a version of CPython from python.org. Some questions might even lead people straight to PyPy.

More and more questions have problems that can be solved by Python 3, but it's probably a pain in the ass if you start with 3 then work out how to solve your problem.