Yup. Unless the GTX560 is cheaper. I'm assuming you are on a single 1080 screen and if so the GTX560 should be able to handle just about anything you throw at it. It's not a bad option it just isn't as fast as the 7850.
Waiting does make sense. The GK104 is supposed to launch tomorrow. IF it performs as the leeks suggest and IF it's priced at $500 it could cause some better cards to move into the $200ish price range. It will probably take weeks for this to happen so you're probably better off just buying now.
AMD did the same thing. 7970/7950 came first, then next month we got the 7750 and 7770. It's really hard to launch all your cards at the same time from top to bottom. The GK106/107 will come, but not until summer according to rumor.