Direct from GRRM himself:

"HBO has given the production order.

They will be filming the pilot episode of A GAME OF THRONES."

If HBO does this half as good as their Rome series I will never ever cancel HBO from my cable subscription to save money. 

How long have we waited for a serious take on a fantasy series where they were not hampered by the censorship of the networks? A really long time!

If it does well I hope we can expect at least a good 13 episode run of the first book or two. Wow!