15" rMBP and Gaming

I'm considering getting a 15" rMBP when Haswell comes out presumably in the next month or two. Gaming isn't what I'm basing my decision off of, but I do want to know how the current models preform.

I'd be using Bootcamp with Windows 7. I'd likely use it for casual gaming as well as games like Battlefield 4 if it could handle it.

Any tips or advice that don't involve "get a real gaming PC" are very much welcome and appreciated as I've never used a Mac for gaming.