What are the possible archetypes in Innistrad draft?
In my Innistrad drafts so far, I've noticed the following as dominating archetypes:

Red-black vampires. This is a classic red aggro strategy, since there lots of small, fast vamps that get big to put a major hurt on your opponent, especially the Bloodcrazed Neonate and the Falkenrath Marauders. The bombs in this deck are the Bloodline Keeper or Olivia Voldaren -- if you see either of those in pack one or two, then jump into black-red vamps with both feet.

Green-red werewolves. This is another aggro deck, though it's slightly slower than the vamp deck since the werewolves are a little bit bigger and take a while longer to flip and become monsters. The Mayor of Avabruck is a good keystone card here, as are the Kessig Cagebreakers -- but really, all of the werewolves in this set are strong enough once flipped to win the game in a few turns. This is my favorite of the current archetypes.

Blue-white flyers (or "Things with Wings" as I like to call it). This deck runs lots of humans, spirits, and angels. In the early game it tends towards control rather than beat-down, since this deck will not win a race against werewolves or vampires, but towards the late game it'll amass a critical mass of flyers to hit for the win. Bombs include the Angel of Flight Alabaster, The Geist of Saint Traft, Geist-Honored Monk, and Intangible Virtue as a key enchantment. In my experience, this is one of the weakest archetypes, since there isn't enough good removal or cheap common flyers to build out a strong deck, and the good blue utility cards are heavily competed for by people playing the following archetype.

Blue-black zombie mill. This is a control deck, relying on removal and counterspells to clear out the early threats, then bring down the skaabs once there are plenty of creatures in the graveyard. The bombs in this deck include Grimgrin, Corpse-Born and the Skaab Goliath. This deck benefits the most from flashback -- conveniently, since blue has the most flashback of any color in Innistrad. There is also a pure mill variant of this deck which I had the misfortune to play against once, when my lucky opponent had managed to draft pretty much every mill card in the set, including 2x Nephalia Drownyard and 2x Curse of the Bloody Tome. This strategy can be very effective, but it's very hard to draft enough cards to make it viable.

Green-white humans should be mentioned to round out the color wheel, though in my experience the synergies among the humans in the set aren't strong enough to really call this a tournament archetype. If you're running green-white you're probably doing it to get the most value out of Travel Preparations, but in that case you'll probably want to construct your deck around white flyers or green werewolves instead, and splash to cover the off-color costs of Travel Preparations.