You only play as a basic Alien in this from a gameplay point of view. In multiplayer, there are skins that allow you to alter your appearance, but they don't make any gameplay changes.
Facehugger: unconfirmed, but not likely.
Chestburster: Logical follow-up to the above.
"Runner": Yes.
Predalien: Most likely a skin in multiplayer, yes.
Praetorian: Yes.
Queen: Not a chance, I suspect.
There's quite a few skins, apparently, so you can probably expect to see some skins that adhere to the films more closely. For instance, Grid from AvP is a skin in MP. Demand from the fans means that skins like the Giger Alien and Cameron Alien may make an appearance, too.