The folks at TechBuffalo managed to get their hands on a BlackBerry Curve 9300 prototype. This unit is still running OS 5 but it's just a prototype. It will very likely eventually run OS 6.
The Curve 9300 has a few new design features like an optical trackpad, flush front control buttons, new media buttons, redesigned volume rocker, and a new back case design. It will also likely ship with 3G, WiFi, Bluetooth, and GPS.