Couple of new ROMs for Samsung Captivate for AT&T have been leaked. Although unconfirmed if the new ROMs are beta ones or stable, the ROM will flash the Froyo-running Captivate to the latest Gingerbread OS (Android 2.3.3).
The builds UCKE3 and UCKF1 can be flashed via Odin and is available for download from Samfirmware.