Amazon might be offering an Atlantis set at 2:00 PST as part of today's lightning deals. The upcoming deal is only described with the cryptic "We Found Atlantis!" label, but doing a quick search of Amazon's toy site, Lego Atlantis sets are the top returns for "Atlantis".
If I had to guess, I'd say it would be the 8078 - Portal of Atlantis. The name seems to fit, they have more than 1000 in stock and they knocked 40% off the World Racers Desert of Destruction on Monday morning, so they aren't afraid to discount the big stuff.