Now that the finale has aired, and we got our first glimpse of Elsa, here's what I want next season: Elsa revealed as NOT the Big Bad.
I want her to be angry and powerful. I want her to be looking for her little sister, who was taken from her years ago just before she (Elsa) was imprisoned in that urn. I want Rumpel to be the one behind it (and not because she actually wronged him, but because she refused to help/ally with him and he was just being an asshole in return) and I want her story to parallel Emma's with her new baby brother (I refuse to call him...that name and I hope the premiere episode reveals his middle name and that's what he goes by). Emma will love that baby deeply, as much as Elsa loves Anna, so what better way to incorporate the inevitable flashbacks than by showing their similarities?
This would also provide great story potential for Rumpel. Imagine, the big threat of the first half of the season is not truly a Big Bad but someone with a completely justified reaction to Rumpelstiltskin's evil. Imagine Belle jumping to his defense like she always does, refusing to believe that Rumpel could have done something without a "good reason", only to learn of his personal betrayal with the dagger. I'd love to see Belle finally be confronted with Rumpel's true nature and for the blinders to come off for good. She'll end up forgiving him, of course, but it would be nice for him to actually work for it and for her to forgive without ignoring.