I'm not too thrilled by the prospect of a Kate-centric episode
I don't know very many people that are any longer. I lost interest in Kate-centric episodes in Season 2 and lost interest in her character altogether shorty thereafter.
Honestly, her character could die and I wouldn't bat an eye. Juliet or Sun are far more compelling characters now. That being said, it'd be nice if there was at least 1 other strong female character on the show that could take Kate's place. (Though obviously I haven't decieved myself into believing she's going to bite it before - or even likely after - the finale.)