This is one of the better video teasers I have seen for quite awhile. While lessons from Forgeworld could still be had, this campaign book looks to be a good one, and something that if you collect digital books (especially interactive ones) you may want to pick up.
Here is a link to the video with Leviathan...... look an image of Sisters is in the video!!!
https://www.youtube.com/watch?v=YSZh-g2Vo08#t=23
Other videos put just recently by Games Workshop include the following