What do you mean with "In PIP"? Are only 5% of the pip downloads from Python 3? That would make sense seeing as pip is included in Python 3.4, so there no need to download it.
If you mean that only 5% of the packages on pypi.python.org is Python 3, I would say that sound a bit low. Also unimportant for most, if it's just the correct 5%. There's also a ton of old cruft on pypi.python.org that would count against Python 3, but not really be important to anyone.
Aaah okay, makes sense. I would like to see new stats though. It wasn't until Python 3.3 we started switching, before to many 3rd party libraries where missing.
Still I don't see much reason to not switch at this point. I don't believe that most developers would be missing anything.
Small note: We run our own pypi server for a large number of packages, so our Python 3 installations aren't counted for everything, but the same should be true for many Python 2 setups.
If you mean that only 5% of the packages on pypi.python.org is Python 3, I would say that sound a bit low. Also unimportant for most, if it's just the correct 5%. There's also a ton of old cruft on pypi.python.org that would count against Python 3, but not really be important to anyone.
Quick check, there are 7633 Python 2 in the package index (https://pypi.python.org/pypi?:action=browse&c=527) and 8949 for Python 3 (https://pypi.python.org/pypi?:action=browse&c=533)