Screenshots on Serebii.net show the pig using fire attacks and the grass one using a grass attack. I think it's reasonable to assume that Black/White is sticking with the Grass/Water/Fire system.
It's likely that the other is pure Water type, although it could be Water/Ice without gaining weakness to or power over the other starter, if it doesn't learn damaging Ice attacks (maybe Haze). There is precedence for an "icy" Pokemon which begins as pure Water but evolves to Water/Ice: Seel. Except for Bulbasaur, no starter Pokemon has begun dual-typed, although many gain dual-type by evolution (Charizard, Mudkip, Torchic, and all three DPPt starters).
Serebii says the powers are Overgrow, Blaze and Torrent, just like every starter to date.
A screenshot on Serebii gives the pig's Japanese name as Pokabu, which seems to confirm the previously leaked names of Tsutaja for the grass one and Mijumaru for the water starter. My limited Japanese suggests Pokabu is a portmanteau of "pokapoka" (the feeling of warmth through the body, or the onomatopoeia for hitting something, and "buta", pig. Mijumaru may be a portmanteau of "mijuku", meaning immaturity or unripeness, and "maru", a suffix for ship names (and something to do with a mythical sea serpent, which I can only half-remember right now). Tsutaja might take its name from "tsuta", ivy, "tsutau", to walk along or follow, or "tsutae", legend, and "ja", serpent.
Poll
