Donnie Darker reports that, Oscar nominated actress Shohreh Aghdashloo joins the cast as Dr. Kavita Rao, a character created by Joss Whedon in his Astonishing X-Men series. Rao is a geneticist who creates a serum called Hope, which "cures" mutants and turns them into regular Joes, or Logans as the case may be. In the comics, this ruffled some feathers within the X-Men, specifically with Beast, a character we already know to be featured in X3.
I’ve also heard from a few sources that no one is seeing the script for X-Men 3. Brett Ratner and the writers are keeping this thing so top secret that the actors are being fed the lines only as they need them on stage. If this is the case they could have some issues with younger and less experienced performers. Personally I think it’s a bad way to make a film.