It depends on what you're looking for. There are more differences between '11 and '12. My '12 needed a mod to the exhaust for the lift for example that the '11 did not require. The interior of the '11 has a few differences between it and my '12, but they're pretty minor.
The engine is obviously different, and we're still figuring out what will and won't fit there.
I've got a snorkel on order from Rugged Ridge that I'm waiting to get in so we can see if that's going to fit my 2012 as well so I can order a 2nd. ATM they're saying it won't fit.
I ordered bumpers from Poison Spyder Customs Friday. He said the 2012's have a canister that I may have to relocate in order to mount that bumper. I haven't pulled my stock one off yet to verify this, but I seriously doubt he's lying to me about it. He said he wasn't sure exactly how people were making the fit, but he has been selling them to people with 2012's.
So long story short, some stuff will fit, and some won't. Only way to be sure is to ask.