The dev dialogue snippets basically collate all of the talking points that En Masse has been hinting at in various interviews over the past year: There's the action combat, the size of the world and the way it caters to explorer-types, and the focus on the action instead of the UI. There's also a quick blurb about story from lead writer David Noonan, specifically the fact that TERA's story (and the world itself) is the dream of two ancient gods. En Masse VP Chris Lee even drops a hint about guild housing, which mitigates the fact that we've seen a lot of the footage in this video before.
There is some new stuff, though, so make sure to keep watching past the titles at the three-minute mark for additional footage. Click past the cut to check it out.