I read a thing online a week or so ago about when the next book comes out. There is obvsly still no official date, but some nerd took the time to look at GRRM's blog, correlate his daily mood postings, and compare that to the last three or so books timeline for ramp up, release, etc and he argues that everything is pointing to a release very soon. He then went on to calc out the words per day production of the last several books and chart that. He has a chart that shows the book coming out as early as late summer this year, to fall 2017.
In summary, it is pretty crazy the amt of time some nerds have on their hands.