GRRM isn't my bitch, because I refuse to read his books until he finishes the series. Already been down this path with the Wheel of Time (and respect that Jordan chose to do what he could to get his ending to his readers).
Martin and other authors are hurting the genre, IMO. I will simply not read any 'epic fantasy' series until the author finishes it - and it is due to the failure of Martin and authors like him (Melanie Rawn, anyone?) to fulfill what I believe is at least an implied agreement. It may be 'art' but it is also 'product' and a writer who can't produce will find himself with a hobby instead of a job.
(The one person who gets a pass from me on this is Brandon Sanderson....because he has shown himself to be not only very good but prolific as well. He's also young enough that I actually believe he will finish the series he has started.

)