To be fair, TERA had a moderately sized booth at E3. I'm moderately excited for the game, so I went to check it out.
They told us a fair deal about the new "Political" systems, whereby players gain control of a territory through either PvP or popular election. But way cooler was that for press, two of the devs led three others (including myself) through a pretty standard raid. The two devs played tank and healer, directing us through voicechat...we were DPS, though I played Archer specifically.
I had a lot of fun, using the C-key hop-back to stay out of the dragon's range as it charged around the map. I was primarily assigned to take care of adds, so I only gained aggro once (we had a close-range DPS getting a shitton, though, he had to be revived at one point), and I didn't really know the differences between a lot of my special abilities, but it was still fun. (The rapid fire shot was quite enjoyable.)
I had a blast, anyway.