The S3's S-Beam "augments" the normal Android Beam, by using Wifi-Direct for large files instead of using bluetooth. I'll guess in the next version of Android, Google adds the Wifi-Direct support to the native Android Beam.
Yeah. This is one of the few times where the 3rd-party version is better than what is built-in the "Google" version of the OS. The file transfers using Android Beam are too slow to be useful, but using wi-fi direct would make it way better.