It offers the revanent as a ninth class option. It will unlock elite specs (endgame traitlines) in PvP. If you just have the free version of the game, buying the xpac will lift some account restrictions (allow you to travel to PvP and central cities sooner, fully unlock the trading post, give you a little more storage, and give you more freedom mailing and chatting with other players). The rest is all level 80.
If you’re undecided, I’d say wait till you’re closer to the cap to purchase. It might go on sale in the meantime. However, if you’re really excited about the revanent or playing a lot of PvP you could go for it now. If you’re talking about a free account (not what you have, since you’re posting here, but maybe a friend’s?) there’s a lot more reason to buy the full game immediately, but no barrier that seriously blocks progress.
We’re going to devote our energies to sports, gardening, all the cultural pursuits;
in fact, we’re going to put the goons to sleep.
Meanwhile – we dig.
