We are not talking about future games here,Snoopy asked about 560 model but since he bought 460 not even year ago i told him its not worth buying that card and paying like 200 euro what gonna give you 20% better FPS rate cause 560 is a speed boosted 460.
Only in case if you building PC from ground as you did buying 560 or 570 is good offer instead of selling 460 for less than 100 euro as used card,cause that card isn't that bad.
New games won't comment but gonna tell you that cards from mid segment gives similar FSP rate as cards from high end segment if you test them on lower resolution as 1280x1024 or 1366x768 with maxed details.
Pure power of 570 or better you see at 1600x1050 or higher resolution but not all PC users own monitors 22''+ at their home at this moment,there is huge percentage of people who are still fine with 17'' or average 19''