What's going on at Amazon?
http://www.amazon.com/gp/product/B009APQ9R4/ref=sr_1_1?ie=UTF8&qid=1350868895&tag=w354&sr=8-1&keywords=zero+escape
3DS Version with Bonus available for pre-order again?
That's not terribly surprising--the same should happen for Vita at some point as people cancel orders and Amazon has a better idea of how many copies are actually going to make it to the point of shipping.
(I had both watch versions preordered, but cancelled the Vita late last week since I decided 3DS was my preferred version. That copy's gonna end up sold to somebody.)