We do not have any definite dates.
Soulbound Studios has not announced any.
If you want to keep an eye on things and see how close we are getting... Here is a rough overview of the Timeline. Things will happen in roughly this order.
Ongoing Website Upgrades <--We Are Here
Prologue: The Awakening (Offline Demo available to all backers. Part of this was Demoed at Penny Arcade Expo this year)
Domain and Settlement Selection via Website (If you plan to be a noble...you probably want to have backed by this point, or you're going to be getting the absolute leftovers in terms of territories)
Kingdoms of Elyria & Elyria MUD (Website-driven games that serve to establish the political and diplomatic climate of each server prior to launch)
Alpha 1
Alpha 2
Beta 1
Beta 2
Exposition (Backers at Bloodline Tier or higher get into the game. This is NOT the same as playing the game, this is a heavily restricted time in which the land-owners get to build up their stuff, and place all of their backer rewards before the game actually launches)
Game Launch
As I said, there are no dates announced for any of these...but it shows you their roadmap.