I know almost sure that they will be together,there a so many hints,from Misty and from Ash's side:Listen to the songs and watch the episodes: He protects her and became Jealous in the Danny and rudy episodes,and there are so many more hints,that I don't know where to start.I hope that this will be the end of the series:
after Ash became a pokemon master,and Misty a waterpokemonmaster,we see a episode from 5 years after the league.
Ash and Misty are married,and living in Pallet town.They have a child:a boy with black hair(Ash) and Blue eyes(Misty) His name will be Ashley.when he became 10 years old,he will start his own journey to become pokemon master.his first pokemon shall be a pikachu or a pichu,and on his journey he shall meet a girl,and they will travel together.
When we see Ash and Misty waving him goodbye,there is a rainbow and a Ho-oh flies over..and we hear the words:
How it all began,and how it will begin again....
and that will be the end of the series.. ;)
(I hope)
The circle shall be round again..