I wouldn't say that they've jumped the shark. The correct term is probably blowing their wad. They're using up some dramatic moments that they might have prolonged a bit. This show has to be all about foresight, since it's going to be something like 15 years before Bruce becomes Batman.
Jim has to lose, too. He can't beat Penguin, he can't be Falcone, he can't beat Maroni, he can't beat Riddler, etc. The only ones that he can really "beat" are Fish Mooney because she's original, and Victor Zsasz because if this show really is "supposed" to be in continuity with the Nolan films Mr. Zsasz is in Arkham during Batman Begins.
This is an awfully long time to wait. They might have had the Wayne's killing be a flashback and gone cold, then jumped a couple years ahead in the first episode with Jim getting a lead.
The show is doing a great job of straddling comic and serious. That campy show from the 60s seems like it's never going to leave the public consciousness, and people seem to expect funny stuff from Batman. At least here the gags are pretty good; we get people going splat, Harvey repeatedly getting knocked around by perps and Oswald just being Oswald.
What I feel is too obnoxious is how the beat us over the head with stuff, especially in the pilot. Every other shot seemed to be "OMG! This is Penguin! Watch him waddle! Notice that he uses a penguin-themed alias!", "OMG! This is Riddler! Look at the question marks! Look at them! See how he makes lots of riddles?!", "OMG! This is Catwoman! She looks just like a young Michelle Pfeiffer!", "OMG! This is the Joker! He's making jokes!", "OMG! Poison Ivy! She's standing next to plants! And now she's standing next to more plants!"
I like the more subtle nods, like how they did with the venom. That also sets up the timing of Bane's origin nicely without beating us over the head with it.