Wow, THAT was a good episode!
The next episode sounds huge! Almost as though it could be a season finale, even though it won't be. Here's my thought on what the announcer said.
Someone big is going to die. This may sound awful, but I'm hoping it's Henry. He has been a little jerk this whole season and maybe I just didn't pay attention last season. But I hope that if he's the one to die that it's done in a heroic way, like he sacrifices himself to save everyone else (or Regina! Ooh!). But considering he was the driving force for getting Emma to Storybrooke and he was Regina's only love in her life and main motivation to be good, it could be interesting to see where the characters would go minus Henry's annoying self.