The cast includes:
Sheryl Lee Ralph- Margo
Eve- Jean Louisa Kelly
Kevin Earley- Bill
Veanne Cox- Karen
(Per Playbill.Com)
These are all very talented performers who can sing, dance, act, and be funny.
They all are TERRIBLY mis-cast, however!
I hope I'm wrong but I can't see any of them doing a credible job in these roles.
Margo should be someone more recognizable such as Diahann Caroll or Stockard Channing (to name just two). Faye Dunaway would have been perfect too.
Eve should be cast with a 20 something actress.
Bill should not be 20 years younger than the actress playing Margo and Karen should be a Blythe Danner type.
Also, it sounds like they're going to use the absolutely awful revised Paper Mill version (which has Margo singing Applause instead of the "Bonnie" Character among many other changes).
"It does what a musical is supposed to do; it takes you to another world. And it gives you a little tune to carry in your head. Something to take you away from the dreary horrors of the real world. A little something for when you're feeling blue. You know?"