I know May 3rd isn't that far away...heck, 2 days. But more than likely what you'll find out on May 3rd is that the Galaxy SIII is launching internationally in a few weeks and in the US later this year. Later this year means fall/winter. I applaud you for waiting till the 3rd to find out more info and being an informed consumer...but I think you'll find out you're in for quite a wait for the SIII.
Edit: Galaxy Nexus or One S are both great phones. It just depends on what you'll be doing with them as to which I would recommend. Power users that root and run custom roms love the Nexus. If you just want a nice phone with a beautiful UI and you're not planning on modding, the One S would probably be the way to go.