Lore is a tricky thing. As an MMO player looking closely at overall world lore can be awesome, or a pure let down. I think games are defined more by their immediate circumstances. Your character, playing with your guild or friends in different situations, really makes up the more recent approach to MMOs. TERA is designing a world that puts all of the races at odds with the races of the underworld. The Argons are the overall enemy and players their wrath.
When building a world overall you need a lot of core elements. Deities for example, TERA has two. Shara, one of the titans in the game, dreams of what look to be the darker races. Vampirs and Naga among them. It looks like the NPC races will be somehow linked to Shara throughout the game. Arun, the game's other deity, dreams of the player races. The Elves, Humans, Poperis, etc. all seem to be linked to a single deity. These two titans make up the basis of the world as well as the names of the continent where TERA takes place.
With each of these beings starting out with godlike power they eventually go to war, as all things do. The twelve godlike beings are not really talked about after that. They kind of disappear in the lore and are taken over by the mortal races. In some ways, each race embodies their original power. Still, all of this remains under Shara and Arun who are sleeping and dreaming of this world.
Choosing one deity for all of your races can be easy. It makes life very easy for players and developers to focus on one form of religion or belief. The world seems to be dominated by the banded races against the Argons so we don't know how much the two titans really come into play in every day activity. Still, I personally like the idea of a pantheon of gods. Blame it on my early age readings of the Greek and Norse gods. I just feel like this gives a player some choice and more opportunity to define themselves. While each race has its own godlike origin, the focus is more on the mortal races defending the two sleeping titans.
The origin lore is interesting enough, but again I think the focus of the game is on the day to day of the characters. Some beasts have been shown and are very unique in design, from what we have seen they are parts of the Argon invaders. The one creature that stands out in my mind are the giant crabs being driven around by riders. The design of the creatures gives a very unique look. The more Argons we fought and saw in the demos the more this style of east meets west creature design was clear.
The bestiary on the TERA site does not reveal much. The Orcans clearly resemble Orcs in the world and look to be a typical NPC faction. The other race shown is the Ghilliedhu who are more like Treants. These big monsters have some smash and slam techniques in combat. How these creatures play into the full story line still remains to be seen. The new twist on classic fantasy races is refreshing.
Overall I think the TERA world has a lot to offer. There are different ideas and themes that help to bond the races together and keep them working towards a greater goal. Something a game with very strong PvE ties needs. Putting players in a desperate situation against an onslaught of opponents can do wonders for community. With little information out there hopefully we hear more about the TERA world as we get closer to launch.