You'll be exploring the titular Lost Frontier as you help Kiera on her "quest to become a Sage and save the world from the threat of darkness." Emphasis is being placed on "sky-high adventure" as you take "flight in one of five different aircrafts" and "blast airborne enemies and battle skypirates with your powerful Gunstaff" -- a new transforming weapon.
The game is being developed by High Impact Games -- the developers of Ratchet and Clank: Size Matters. We're glad to see Daxter's name back up there in the title. Hopefully it more resembles the colorful fantasy world of Jak and Daxter 1 than the depressing GTA-esque Jak 2.
Update: Just in case you're still scared that this is an April Fools joke, here's a quote direct from Sony: "Nope -- not an April Fools." See?