I think the showrunners really handled this wrong. Grey's Anatomy did it the right way -- you act like nothing's wrong, keep filming the show business as usual, finish the season and... what's that? You have a plot point in the story that allows you to get rid of the actor seamlessly?
Yeah exactly. Film a few episodes with him in it then say he moved away.
I don't care if the show is canceled however if they want to save it I'd have the brother finally grow some balls and move into his own place. Maybe he even comes out and the new man can be his boyfriend.