Servers were switched on today at 9 AM PDT / 12 Noon EDT, so the game should be playable right now. The beta is scheduled to run through January 19. Servers will be officially switched off on that day at 8 PM PDT / 11 PM EDT.
The Evolve open beta on Xbox One features two playable Monsters (Goliath and Kraken), eight Hunters, and 12 maps. Starting January 17, players will be able to try out the Evacuation mode.
All Hunter and Monster characters unlocked through the Evolve beta will carry forward to the full game when it launches on February 10.