Tor.com have released Darrell K. Sweet's sketch for 'A Memory of Light'.
There's a bit of a furore over in the comments section and no doubt elsewhere on WoT sites regrading if the sketch is a massive spoiler. Tor didn't help themselves by describing what the picture is of. "The scene depicts Min, Aviendha, and Elayne gathered on a battlefield around what is presumably a funeral pyre for Rand al’Thor, the Dragon Reborn." Yeah it's obvious but saying that removes all doubt. People should remember though that Sweet's covers haven't exactly been accurate depictions in the past and I'm pretty sure that scene doesn't depict the prophesy that's in the books(three in a boat).
Anyway I don't see why they just didn't use this sketch as the cover(if they had family permission). Sure it's not the finished polished cover, but this is the final book and what's on the cover isn't going to make people buy it or not. This sketch is better than some of the finished covers IMO.