I would not say that the quality of the books have gone down, they have however been given a more political perspective (which I happen to find just as intressting as heroes travelling in the wilds).

But I don't think he can close it up to book 13, he have said himself somewhere, don't remember where that he will need at least three books to just finish it. And I would acctually, belive it or not read ten (twenty in the swedish translation because they cut the books into two halfs) more.

But I am afraid that Jordan will die before he can finish the books in that case, and then I would be a bit angry. But I think that book 14, or maybe 15 is the earliest endings book. But I could be wrong of course.