Not that it matters much, but it looks like the US bound Galaxy S 3's will use dual core snapdragon's, not the quad core chips.
Seems the rest of the world will apparently get the quads at this point, but not the U.S.. Reminds me of how a Nexus model (I believe) was significantly different between the AT&T model and the Verizon model if my memory serves.
While it would seem a serious stretch that you'd need a quad core processor in a phone or tablet, its the way the chip industry is increasing performance and will continue to do so in the future - so it will be up to the OS makers to take advantage and harness those cores. I'm sure Apple's hardware will get quad cores as well at some point. On its face I think I'd rather just have dual cores and a die shrink to significantly reduce power usage, but that's not where things are headed (nor have they been)....so be it.