According to Amazon, the Galaxy S3 is now shipping for AT&T for $189.99 (including a contract of course). I think that's the first carrier to actually ship this phone in the US. The Galaxy S3 US model has a 4.8" 1280x720 HD Super AMOLED (with Pentile), a dual-core 1.5Ghz CPU, 2GB of RAM and an 8 mp camera (1080p video) and lot's of new software features. The phone weighs 133 grams and is only 8.6 mm thick.
The S3 pre-order numbers were very strong, and it seems that Samsung has another winner at their hands, we'll be sure to hear from Samsung about actual sales numbers soon.