what is it you really really can't wait to see? Give the two or three favorites.
Mine:
1) Replay and teaching tools: Tools that make it easy to share knowledge, experience and ideas are my undisputed number one. I even hope that Kaya will provide tools so good that it will be attractive to start a carreer as online teacher on it. I will be a student, not a teacher, though.
2) Skins for goban and stones: I know it sounds silly, but aesthetics are an important part of the game for me. I want to be able to chosse a good looking goban
3) Some kind of tsumego mode: Would just be awesome! Less priority than 1) and 2) though.
Jörg