My ideas :
The Pet Derby and Pets fighting seem interesting. It seems it would require a full set of stats for pets, in addition to, say running and jumping for the minigames. The Pet Derby makes me think that it will be a triathlon of sorts, made up of a few little minigames. From the Picture revealed alongside Celestia, I think the hatchery will in some way not only make a new pet that looks like the two "parent" pets, but in some way will combine their stats. If so, I am totally combining my Colossus' strength with my Clockwork's speed (Anyone who has done Marleybone knows how obnoxiously fast they can run). And maybe I'll pick up a storm bat for flight. Me and my Ice Clockwork Bat shall be unstoppable! MUAHAHAHA!
I am also intrigued about the leveling of pets. It says they can be raised from eggs to Ancient Beings, but how does that work, exactly? I suppose we'll see..
Until next time!