Entertainment Weekly has announced that next month Random House will be releasing another chapter from George R.R. Martin's The Winds of Winter. The chapter will come as part of an update to their A World of Ice and Fire App and will be the first Tyrion chapter from the upcoming novel.
Somewhere off in the far distance, a dying man was screaming for his mother. “To horse!” a man was yelling in Ghiscari, in the next camp to the north of the Second Sons. “To horse! To horse!” High and shrill, his voice carried a long way in the morning air, far beyond his own encampment. Tyrion knew just enough Ghiscari to understand the words, but the fear in his voice would have been plain in any tongue. I know how he feels.
Unfortunately, that is all there is of the preview, so you'll have to wait until next month for more... unless you want to read the summary that was leaked a while ago from a public reading Martin did of the chapter.
No word yet on the target date for release of The Winds of Winter. Hopefully Martin does plan to dish the story out as two chapters a year.