Quote from link.

We had collected some interesting wishes from DBO fans here.

Wish 1: Can you help me to change someone's character like this style?
Wish 2: Can you let me keep the dragonballs forever?
Wish 3: I wanna watch a fight between characters from Dragon Ball and Naruto...
Wish 4: Bestowed me a flying riding ulap as Goku's, please!
.......

So when you have gathered all dragonballs, what's your wish?