I thought Letts was rumored/announced to be involved in the Chicago at some point, so I must be either making that up or remembering wrong. Especially since the Chicago production is directed by Amy Morton. I'm not super-familiar with Steppenwolf, but I notice that there's only one "ensemble member" in the cast (James Meredith, who plays Albert/Kevin); is this common?
As others have said, this play is a true ensemble piece with rich roles for many different types. I'm excited to see who they'll cast.
"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