Ariel is a recurring character, since she'll be back next week in Storybrooke. So she might get a happy ending after all if she runs into Eric there. Eric and Snow White were contemporaries, so he should still be around too.
Nice they kept Ursula as a separate character at the very end, they fooled us with the "Regina is Ursula" thing.
I've seen the actress playing Ariel since I was a kid, since she was on "Are you Afraid of the Dark" in the early to mid 90s.