It was recently announced that the closed beta for Mirrors Edge: Catalyst will be taking place on April 22nd for the Frontrunners and April 23rd for everyone else, and run until April 26th. If you want to sign up and try to be a Frontrunner you can do so here and if you don’t get chosen for the first day, then you may be chosen the next.
Available in the closed beta will be a few missions from Faiths’s main story, some side missions and other pertinent content important to the game. A type of social play is also mentioned, which could be multiplayer levels like races or team missions. For more on social play check out the following video