Jayce's passive belongs in his ultimate
Currently his passive says "Gains 40 Movement Speed for 1.25 seconds and can move through units each time Transform is cast." But don't you think that it belongs as a part of his ultimate rather than his actual passive? So if the champion design team really believes he doesn't need a passive, I'm ok with that. But don't try and hide it, have some fun.
For example: New passive idea: Awesome Weapon : "Jayce carries an hammer that transforms into a cannon. Freaking awesome." And his old passive is moved to his ultimate.