The good news is that the closed beta for Mirror's Edge: Catalyst begins on April 22 and lasts all the way until April 26. The bad news, however, is that the closed beta sign-ups are now, well... closed, and only those that signed up for the Mirror's Edge 'Frontrunner service' (a fancy name for a newsletter) will be eligible to join this phase of the beta.
While the closed beta will only feature a couple of main and side missions, the social play features such as time trials, races, and various others should in theory provide plenty of replayability. Here's a brief DICE video explaining the whole concept of social play and how the multiplayer features will work:
Personally, I don't think I can care any less about having a social profile in Mirror's Edge, nor do I plan to go through the trouble of ever going to the website or installing a companion app, but the idea of having Dark Souls styled multiplayer features is a rather interesting one. Being able to compete in player-made races while dashing alongside the "shadows" of other runners doing the same thing is the sort of multiplayer I could see keeping Mirror's Edge: Catalyst engaging even after the campaign runs its course.
Whether the execution is going to be any good or not remains to be seen, but with April 22 nearly upon us, we at least won't have to wait for very long. Mirror's Edge: Catalyst will be releasing on May 24, alongside some serious competition from both Overwatch and Total War: Warhammer.