Interestingly enough, a sky realm would be the right place to discover a guy that travels around by hanging himself from a balloon and makes maps. If there were to be any character to obtain a map of the sky it would be him. Possibly over one of the random remote islands way out on the horizon. He could also serve a similar role to the fishman of WW, by giving some slightly useful hints on what may or may not be on a couple of the sky islands floating around. Although I think the bait will be cheaper than what you would have to pay Tingle for his info. I can only hope that it would not be required to continue the quest, I think that was the most annoying aspect in WW. You had to keep paying him incredible amounts of rupees to complete the quest.
This could also work out with some of the other connections I have noticed before (my own theories though) since I keep thinking that the goddess statue in Skyloft closely resembles the great fairies of ALTTP. While most agree that Phi resembles the fairy queen of WW. I would like to see any hint of an origin to Tingle's fairy obsession. Even if it did begin with viewing Phi nearby Link. She is confirmed by developers and in game text to have a "treasure seeking ability." I think it would be interesting if that alone was Tingle's real reason behind his neverending quest for fairies. Well that and they do have the capability in WW to increase one's wallet size, this fits with Tingle's money making personality fairly well.
Even then, I would not at all mind see a nod character like Purlo of TP. How fun would it be if Uncle Rupee was actually a demon alongside Ghirahim? He could represent greed very well.