The pantheon of fantasy authors is diminished. His books were intriguing (at least at the start) and he had a grand vision that will probably now never reach fruition (though, it seemed unlikely it would have while he was alive).
Imho, Wheel of Time began great and then was crushed by the twin pressures of overserialization from the publisher and Jordan's own massive ego. I went to see him at a book reading, and he spent the first ten minutes lecturing the audience on how to pronounce the names of his characters, because apparently we were all getting it wrong and this really irked him.
Anyone who's read the series has to admit that the later books... maybe 6-9, were stuffed with unnecessary padding, to the point where they were a near thousand pages of fluff with one hundred pages of action at the end. This became Jordan's mode of operating in the later years, and it made reading his books such a chore that I gave up entirely. All the while he insisted that the series would have closure, that dangling plots would resolved, that all would be well and his prodigiously overstuffed world would make sense in the end.
Well, here's the end, and Jordan fans may never get their resolutions, unless his notes and outlines are as detailed as his survivors claim.
But I suppose it makes us more thankful that some writers have the vision and forethought to actually bring their series to conclusion (Rowling, Bakker, etc.). I'm not faulting Robert Jordan for dying--only for choosing to spend a good chunk of years, during which he knew he was afflicted with a debilitating disease, writing more fluff, including a set of prequels to WoT.
The only way Wheel of Time can be redeemed, in my opinion, is if a thoughtful and devoted editor takes up the entire project, books 1-12, and pairs them down into an abridged series. I imagine this would be roughly half the length of the original.