There is an interesting parallel with Python 3, which was released around Christmas 2008. Python 3 code is not backward compatible to Python 2, but there are much fewer differences between Python 2 and 3 as there are between Perl 5 and 6. Mostly the code got tided-up and deprecated features removed.
in reply to The current state of Perl6
So, is everyone using Python 3 now? No. The reason, according to the Python people I have spoken to, is the lack of third party modules. They like Python 3, but just can't use it. Let's hope that 'we' learn from that mistake before repeating it.