Kevin,
It's important to note that there are different models of the S3. The international version is the quad-core with Enyxos being sold around $600 off-contract. While Sprint, AT&T, Verizon, T-mobile sell the 1.5Ghz dual-core at the subsidized $199 price. You go on to say how the new Nexus will probably be cheaper than the S3 because it uses the dual-core chipset. With a 2-year contract, I would think the price would be the same $199. Off-contract, if they could retain the same pricing as the current Nexus being sold on Google Play ($350), that would be awesome as the dual-core S3 is sold through the major carriers for $550.