A recent flurry of minor roles have been cast for the series, although I was waiting for the final word on the last few parts before putting up the last big casting update. As of right now, we have 100% confirmation of Isaac Hempstead-Wright as Bran Stark, Bronson Webb as Will and Esme Bianco as Ros (the first created-for-the-show character, a prostitute in King's Landing), whilst Twitter posts indicate that Jamie Campbell Bower (who is appearing in both the new Twilight and Harry Potter movies) has landed the short but memorable role of Ser Waymar Royce. We're also waiting for 100% confirmation on Ser Rodrik Cassel, Gared and Benjen Stark as well.
As of right now, the sole speaking part in the pilot that remains unconfirmed is Khal Drogo. Maester Luwin and Ilyrio Mopatis were the last roles to be cast, although their actors have not been announced yet (although Donald Sumpter has been suggested for the former and the excellent Ian McNeice as Ilyrio; whether that works out or not we'll have to wait and see).
Finally, shooting for the pilot beings on 26 October. An at least partial and possibly full cast reading was held yesterday, and apparently was a solid success. Some additional crewmembers have also been added to the roster, with the recent news that Modern VideoFilm will apparently be working on the project in some capacity, probably involving digital effects.
So it's looking like we should have the full cast list in a matter of days. It's been a bit of a long haul to get here, but it looks like the pieces have finally fallen into place.