Looks interesting. I liked the story trailer one towards the end when the last character left standing against the giant Buddha demon is all like, "Imma die but my panties are hawt!" and then the old guy standing on the hill was all like, "Yup, them were some hawt panties."
The gameplay footage was obviously test footage. Did you see the respawn rate on the pack of mobs she killed? It was in the neighborhood of 30 seconds. Also, for a rather large pack of demon type mobs, they were non-aggressive, which suggests more of a combat systems test setup than an actual, "You'll get to fight this exact same group of mobs in this exact spot, too!" kind of thing.
FFXIV is being marketed as a game where the combat will feature, "many vs. one" and "many vs. many." If the idea of fighting multiple enemies simultaneously truly bothers you, I guess you're in the wrong place.
Tera looks like a pretty game and from what little we've seen of the combat footage, it could do well. There's a lot more to an MMO than bewbs and basic combat, however (AoC showed us that). Can't say I'll be following Tera with an eager eye, but I've seen worse.