looks like the price of the seagull has dropped from 60 tol barad commendations to 48 as of the latest beta patch. it still requires an honored rep with your alliance/horde tol barad faction.
tol barad seems to be similar to the wrath of the lich king's wintergrasp. (not sure about the actual PVP, but in terms of zone and access, it's not that different.)
it should be noted that there are two sections to tol barad - the actual battle field where the pvp takes place, and tol barad peninsula where your faction's NPCs and other things are located. you must be level 85 to take the portal to the peninsula, but you can queue up for the actual battle at level 80. unlike wintergrasp you cannot fly within or directly to either zone.
once in the tol barad peninsula (not the battle field), you'll find your faction's quartermaster and some daily quests. the dailies will earn you a tol barad commendation (and some reputation, i'm guessing) once completed.
there may be other ways to earn the commendations (winning the battle perhaps?) but i haven't had a chance to find out.
so the seagull companion may be a pet that we'll have to wait until we're 85 before going after, but who knows. if we can start earning tol barad currency early on, maybe we'll be able to buy it by the time we hit 85 (when we can port straight to the quartermaster.)
personally i'm not all that excited about it. i've never had any interest in pvp of any kind. but if it's for a vanity pet... i will suffer through it! *determined* i might have to drag some friends along to help out and keep me from ripping my hair out though.... ;P