From the developer's page:
A particle physicist’s mysterious and spectacular death sparks a race to find his hidden vault and claim his terrifying new discovery. The player will take control of four characters whose lives become entangled in the search for the scientist’s vault. They will have to learn to trust each other and work together to overcome the obstacles in their way and to keep this new and powerful technology out of the hands of a dangerous organization.
We've been involved for about eight months now. And by "we" I really mean my wife Janet. She took over as lead programmer and has been working on it full time, and it is nearly complete. We've also recently started recording the voiceovers, which have been truly stellar. New to our cast is Logan Cunningham - known as the "narrator from Bastion" - and he is joined by Wadjet regulars Sarah Elmaleh (Jamie from Blackwell Deception), Daryl Lathon (Theo from Puzzle Bots) and Edward Bauer (Jeremy from Blackwell Deception).
Since the cat was let out of the bag recently, we figured it was a good time to let you know what else we've been working on. And while we don't like to commit ourselves to a release date until we know for 100% sure when it will be finished, we are aiming for a May of 2012 release.
That's all on Resonance for now! More news will revealed as it develops.