Acording to a tweet from Peter Marks, the entire principal cast is transferring, with the exceptions of Rosalind Elias and Don Correia.
And as someone who saw Clark's performance as Sally three times, I can say that five years ago she seemed to have the groundwork laid for an amazing performance, but fell short of actually following through. That said, she had nine days of rehearsal and wasn't completely off-book in the book scenes (though her numbers were perfect). The way she performed "Losing My Mind" wasn't to everyone's taste--certainly VERY different from Bernadette, but they're different artists--but it mostly worked for me. I'm interested to see what she'll do with the time to properly explore the character.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body