I've seen that army before and it is a conversion using bits from the Mawloc...
Also, if you note this is a promo display with the rulebooks from every previous edition of 40k... If you notice the bottom of the page has previous Nid version including the old Screamer Killer carnifex.
Its not a new book, this appeared before 6th edition with all the Crimson Fist 25th anniversary model stuff.
Edit: Darn. beaten to it while trying to find a reference pic. lol.
No news or rumours here, the pic was debunked last year. It is a shop that has this on display, the 25 Anniversary book with a question mark is just something they printed out themselves and added to the display in anticipation of 40K 6E.
The pic has been 100% debunked, no new units or books or anything. There were threads on all forums, including this one, discussing this picture.
A forum community dedicated to Warhammer, Warhammer 40K enthusiasts. Come join the discussion about Warhammer and Wargaming collections, miniatures, tactics, terrain, reviews, accessories, history, displays, models, styles, scales, reviews, accessories, classifieds, and more!