anandtech's review is most likely based on a preview engineering sample with half finished drivers. you'll probably need pcie 3 capable cpu and motherboard to run the 7970.
wait for the real release in january and reviews. dual 560ti is a pretty powerful combo imo.
also, amd almost always screws up drivers at any launch.
The only way its good is if you are going to spend another $400 in 2012 or 2013 to add another 7970 then its worth selling the 560tis...otherwise they will be identical performance wise. You won't be able to get anything from adding a 3rd 560ti in the future. Also you do get 1gb more ram from 7970. So it all depends on what you can sell it for. You might even sell the 560tis and get a slighlt lower 7000 series card...i'm sure it will be better than 560ti for the same price...all in all the moment 7000 series hits...all existing cards will diminsh in value so make you decision asap before the 9th of Jan.
Another thing to consider is that a single 7970 won't give you microstuttering like SLI and crossfire . Thats a matter of personal choice though.