All forces involved will get at least one special, the book states, but some will be in book 2 .
Howling Griffons - chaplain dread
Astral claws - Lugft , a company captain and their master of the forge
Marines errants - captain , give one tact squad a couple of universal special abilities(Move through cover & scout) , also gives that squad a bonus for the ship fighting rules.
Red scorps - an upgraded cullen and their chief librarian.
Fire angels - a captain that allows CT to be replaced with tank hunter and all rhinos get the extra armour upgrade.
Raptors - chapter master with a fairly amazing bolter and can replace CT with stealth. (i like this one the best)
Lamenters - chapter master (uses the blood angel codex , apposed to all the other armies which use the standard codex space marines)
Novamarines - Captain , makes termies (both types) scoring
Firehawks - captain (possibly the best model for the points) jet pack, sort of a relic blade, replaces CT with free twin linked flamers and heavy flamers, assault squads and vangaurd count as scoring.This character nearly made me start this chapter, but its such a horrible paint scheme.
other chapters and their specials are in the second book, along with some new tank types apparently. The assault ram , i assume is in there.