Um, it has been available for ages
Personally I would never use 5.6.0 anywhere I cared about. Some of the bugs were very serious.
5.6.1 is much better, though for stability I prefer 5.005_03.
Hopefully by this summer we will have 5.8.0 which will be a massive improvement in QA. (Massive enough that I am thinking of going straight from 5.005_03 to 5.8.x.)
Cheers,
Ben
"... I couldn't see how anyone could be educated by this self-propagating system in which people pass exams, teach others to pass exams, but nobody knows anything."
--Richard Feynman