IA 12 from forgeworld is mainly a necron book.

Man-of-War Thu Mar 07, 2013 11:17 pm

http://natfka.blogspot.com/2013/03/imperial-armour-12-necrons.html#more

via an Anonymous Source from the Faeit 212 inbox
Necrons get 3 new characters and a new flyer. Which is a bomber-type on a night scythe chasis.

Added On
The canoptek acanthrites are also in IA 12, as well as the tomb stalker. But since those are already on the website I didn't mention it.