Cheering for them.
They played phenomenally against the Pens last night, and I really would rather see them progress than the Pens.
I don't see why people think it's so outrageous to keep watching the playoffs once your team is eliminated, it doesn't make hockey in itself any less of a fantastic sport. Good hockey, is good.. and it's fun to watch. Plus, the boys of course won't be back until next season, so one might as well root for another team until this one ends.
Also, I see nothing wrong with cheering for the team that eliminated you either. I'm not a poor sport or a sore loser, we choked.. and they took advantage of it. There's nothing really unfair about that, doesn't mean they aren't a good team. It was really depressing, especially the way it happened, but I don't hate the Bruins and I wish them the best for the remainder of this season.