Well, as with Jordan, I think you cannot really judge Martin till he finished his work.
Tad Williams Sorry, Memory and Thorn for example is one series that I think started off strong but got a bit repetitive and weak in the end.
(For example, Simon tends to get lost in the Underground somewhere, starving and dying with thirst in just about every single book of the series - not good.)
Likewise, Jordans tale would, I believe have been better with a nice and crisp finish a few books ago.
Moorcock tale of Elric also got a bit to confusing for my tastes in the final books.
Martin, I'm getting the feeling, is starting to fall for the same bloating and recycling of old concepts.
The series already gut bumped up by a couple of books a few times and he'll be hard pressed to keep the pace and novelty of the first three books fresh and going in four more of them.
Given all that, I still voted yes. Martin's series has, IMO, the potential to be the best out there since Tolkien.
One has yet to see if he can life up to it though.