in reply to
Re^3: What is Perl6?
in thread What is Perl6?
... and Iron Python, and PyPy (Python in Python), and Jython, and others. Those are all on Python 2.6 or earlier, although the latest CPython is at 2.7, and only CPython is on Python 3, with Python 3.2 coming out in February.
However, for newbies there is a clear download link from python.org - it is to the CPython release, since that is what most want. Will Perl 6 newbies want to wade through alternative versions? Personally I doubt it, choice is good when you are qualified to make the decision, but newbies will be scared of it (a reason for the success of Windows).
Python 2 to Python 3 involved major changes, but nothing like the number of differences between Perl 5 and 6. Two years since the full release of Python 3 and it is still a minority of sites using it. A major factor in the slow take-up is the lack of ported modules. There is currently a freeze on Python 3 language development to allow everyone a stable target. I'm sure the Perl 6 people are watching the Python 3 experience, and I hope the lessons are being learnt.