No, it's not Aion or even TERA. The new kid on the block is called Bless, and though we told you about the game back in October, it's taken Neowiz a while to come up with an English website. That website is now live (though it does take forever and a day to load). The site features a trailer, a few screenshots and character concepts, and brief snippets of lore that seem to indicate two factions (Cosmopolis and Hierapolis).
We've heard a rumor that Neowiz has more than 150 developers working on the project, some of whom worked on Aion, TERA, and Lineage II. We'll bring you more on the new title as it becomes available.