Python 3 has been around for years. I actually wrote a series of articles for DevX on Python 3 called "A Developer's guide to Python 3.0". The first article was published on July 29 2009, more than 6 years ago!
Python 3 adoption has been slow, to say the least. There are many reasons for this, such as slow porting of critical libraries and not enough motivation for run-of-the mill developers who don't particularly care about Unicode.
But, the tide may be turning. The library porting scene looks much better. Check out the Python 3 Wall of Super Powers for an up to date status of the most popular Python libraries. The clincher may be the cool new asynchronous support added to recent versions of Python 3. Check out "Asynchronous I/O, event loop, coroutines and tasks".
In Python 3.5 there will be dedicated async/await syntax inspired by C#. This battle-tested programming model proved itself as robust, expressive and developer-friendly. Check out PEP-492 for all the gory details. Python 3 may have finally arrived!
Python, syntax, asynchronous, Python 2.7.9