No, because the reference 560 is at much higher clocks. Though depending on settings (like AA/res) on certain games, the extra 256MB of vram could put the 470 over the top if the 560 ran out of vram. Right now I'm tapping out my vram playing CoP Complete Mod maxed at 1920x1200 ... I'm sure a 560 would be a slideshow in this particular gaming scenario.
But generally ... no. 560 is a bit faster. However at max OC if you get a good 470 it's likely to be a little faster because it would have a lot more headroom in terms of the % OC (also hotter and louder though).
Mine, for example, will OC by 40% on the core and I seriously doubt anyone with 2x560's could 'take me'
EDIT: A side-note ... something to keep in mind about memory amount ... having 'more memory' does not inherently improve performance in and of itself. Either you 'have enough' for the gaming scenario at hand ... in which having more does NOTHING ... or you DON'T have enough, in which case your performance goes down the crapper.