The main release is of course the Death Masque boxed set. Priced in the same ball park as Overkill and Betrayal at Calth, this stands out as having decidedly less miniatures than those releases - but what we do get is five full suits of MK 8 Space Marine armour, two exclusive new characters, Eldar Harlequins five Vangaurd Space Marines and a dreadnought. The sprue breakdown that is up does not show any of the new sprues, just the repackaged ones which is a bit of shame.
I wonder if the Deathwatch miniatures are actually MK 8 vanilla and we just get two Deathwatch upgrades sprues to convert them and the Vanguard Space Marines.
*** EDIT - SInce this post, Games Workshop have added pics of the new sprues. The Mark 8 are exclusively Deathwatch. There may be a Deathwatch upgrade sprue in the box, but it wasn't pictured ***
On the same theme, the other pre-orders include the Deathwatch Codex (including a Deluxe version which is almost thge same price as the entire boxed set) as well as Deathwatch Datacards and Deathwatch Dice