The Butcher has left the bedroom door open, though the new kitty seems to prefer to stay on his bed. When I came home, she came out to see me. She hissed at the dog. The dog hid behind me. The two older cats sat on the counter, paws tucked under their bodies, watching intently. The orange cat hissed at the new kitty, just for good measure. And now the older cats are sitting on as high a things as they can find, while the new kitty has retreated back into the bedroom.
So, I think that went well.