The new campaign book Mont'ka has new formations two factions in particular, Cadians and Farsight. Both are getting new Warlord Traits, special rules, items, and tactical objectives. Thats quite a bit, especially for Astra Militarum players like myself with loads of Cadians.
Here are the leaked images for the new formations.
Thanks for linking these up in the comment sections and sending in these links.
Cadian Formations http://m.imgur.com/a/WGbXH
Farsight Formations: http://m.imgur.com/a/vdlig