HBO have released a metric ton of new promo material for Game of Thrones today, starting with the four posters shown below.
They've also released four 'House' videos, one each for Houses Targaryen, Stark, Lannister and Baratheon. The Lannister one is notable for our first glimpse of Charles Dance as Lord Tywin Lannister, whilst the Baratheon one makes a point of mentioning Stannis several times, though he won't be cast until the second season.
Those based in the USA should also note that Comcast have a ton of exclusive videos (USA-only at this time) on their site, including expanded behind-the-scene features and character profiles (including Jason Momoa characterising Khal Drogo as 'the biggest pimp'). Winter is Coming has YouTube links.
Excellent stuff, though I think HBO need to be careful lest they overload the potential viewer with featurettes, posters and teasers. There's quite a lot of material out there now.
Meanwhile, Bantam editor Anne Groell has released a picture of herself holding the manuscript of (95% of) A Dance with Dragons:
Impressive. And in a little under four months, everyone will be able to read it :-)