The cast has been announced. I have not heard of any of them beyond Jennie Garth who is going to play a guidance councilor as her original 90210 character.
90210
Cast: Jessica Walter, Lori Loughlin,Shenae Grimes,Tristan Wilds, Dustin Milligan, Anna Lynne McCord, Ryan Eggold, Jessica Stroup and Michael Steger.