I only got around to watching the episode today, and i actually thought watching it that they were implying that the favour Rumple is going to ask Emma is to kill him. I could be completely off the wall, but I just got a really strong vibe off everything throughout the episode that that's where they're headed.

Also, and this is totally, totally unsubstantiated mind wandering...would it be possible that Rumple's on is Henry's father? I know I read somewhere that the producers said it was possible we could meet Henry's father before we realised it. And to be honest, if anyone could get a child out of Fairytale before Regina cast her spell I think it would be Rumple. It would also give Rumple a reason to be so interested in Emma and be willing to go up against Regina for her. It doesn't explain why he'd get Henry for Regina though and not keep him for himself. Like I said, mindless ramblings :)