So after the latest announcement that GRRM might (or might not) get done with Winds of Winter in 2017, I decided to stop waiting and finally just watch the series.
I started last night.
First impressions: Wow, they took the start of the first episode right from the book. The scene across the wall, and then having to behead the deserter in front of Bran, and then finding the direwolves on the way back.
Casting impressions: The Starks certainly look different than how I'd pictured them. Robb Stark is less handsome. Sansa is older than I was expecting and less pretty. Bran has longer hair than I'd pictured, and looks older. Arya and Jon Snow look pretty spot on though, as do Ned and Cat. The twin Lannisters: excellent choices. Both are very similar to what I pictured, even though I've never seen these actors before. Peter Dinklage does NOT look like Tyrion.
The King is spot on, as is Sean Bean as Ned.
Overall, well done. I even like the theme music for the series, and the opening sequence. In the books, I'm always flipping back to the map of Westeros. So making the main opening sequence basically a map of Westeros is a brilliant idea, and a way to show people the relevant geography over and over at the start of every episode.
It's interesting that after staying with the book opening they switch to a first scene in King's Landing where they show that Cersei and Jaime are somehow responsible for Aryn's death. In the book that was a mystery to me until near the end of the book. And to introduce Tyrion, they have him at a whorehouse in Winterfell? That wasn't in the book, but it's certainly in keeping with the character, so I like it.
Overall, I've only seen 15 minutes, but very positive impressions.