Concerning Jayce

What is the current opinion on Jayce? I don't see him very often, but I've taken a liking to the champion. I think he has a lot of character, and his playstyle certainly has a lot of depth. However, his pick rate seems abysmal. Any particular reason why he's just not used often? From my experience, it seems hard to build much defense on him without it seeming like he can't kill anything, and without Manamune it feels like one rotation of spells is all you can manage in a teamfight. On a side note, I'm really digging the Forsaken skin for Jayce, one of my new favorites overall.

Is Jayce weak? Strong? What could make him more viable/appealing?