I think the previous comments are a bit arsh, true enough the book is somewhat an "in-between" tome but it's empahize and continue to developp ASOIAF's world. The plot is moving slowly but weren't you greedy to know about Lord Snow, Tyrion and Theon, Bran and baby Rickon ? If the news are correct Martin has already started completed a big parts of the 6th tome, so it mayby the series will never end or will in 4 more books. But as the author said, this book "was a bitch", something that is sour and raw to your taste, which will not content you enough, but something good and suprisingly enough to left you hungrier for one more taste.
PS: sorry for the bad english, but that's not my tongue