http://tera.enmasse.com/news/posts/tera-s-second-open-beta-for-consoles
March 16th 6AM PDT through March 17th 9PM PDT. Part of this test will include the server side spinning up more channel instances and presumably, auto load balancing players into those channels as needed (to prevent too many players from being all in one channel). Only those who have the client installed from last weekends initial open beta will be able to participate.
Level cap is also being raised to 58 (Reaper will also be available to anyone who has a level 40 character).
All OBT2 participants will also receive a permanent Blue Angel Halo once the game launches.