I've seen two Game of Thrones references so far.
Near the marketboard in Coerthas, a girl and boy are inspecting a piece of paper. The boy asks, "Is this a P or a R?", and the girl responds something like, "If you'd spent more time studying instead of playing Knights and Knaves, we might have lemoncakes now!"
Lemoncakes are Sansa Stark's favorite dish. I count this as a reference because there are other GoT references in both 2.0 and 3.0, including the achievement "Stick them with the pointy end!"
As a matter of fact, the
trial by combat that you enter after being named as Tataru's champion is something we've seen a lot of in GoT recently. Given that we're now dealing with dragons and a winter climate, I think this was a nod to the series.