I was very surprised to hear this news. Oddly enough while high fantasy is one of the most successful genres in feature films, it's virtually non-existent in television.
The Hollywood Reporter lists the producers of the new series as David Benioff ("Troy"), D.B. Weiss, and Guymon Casady. According to IMDb Weiss has no produced credits yet, Casady's last TV show was "Cavemen" (not very promising), but Benioff has a number of good credits under his belt, which makes the outlook for the show a bit more hopeful.
The producers say that the current plan is to portray each novel over a seasons worth of episodes. I'm assuming that's 10 to 13 eps per season.
Personally, as much as I liked the Martin books, I would have preferred to see another historical drama ala Rome or the Tudors.