Compared to the Samsung Galaxy S II, this phone has a few nifty upgrades. It supports 4G (LTE 700) networks, and has a 4.7" screen, which is an improvement to the S II's 4.3" screen. Additionally, the S3 will feature Bluetooth 4.0. The Galaxy S3 has a 12MP primary camera, which, again, is better than the S2's, which is of 8MP. But the secondary camera has been stripped down from 2MP in the S2 to 1.3MP in the S3; ewww, ugly!
But now come those lil' things that are really gonna make the difference: the OS, and the CPU. The Galaxy S3 will feature Android 4.0 (Ice Cream Sandwich), and runs on a.... wait for it... Quad Core, 1.5 GHz CPU! Outrageous isn't it!
No mention has been made yet of it's pricing and such, but we can look forward to an attractive price tag which will sure convince a lot of people to invest in a Galaxy S3!