Very promising stuff... It's old but it shows us the potential of the G0 stepping.
E6550 "G0" testing 3.6GHz w/ 1.29Vcore, 3.8GHz w/ 1.35Vcore Low Volts, High Clocks! - XtremeSystems Forums
A newer thread that is showing more recent overclocking of the e6550.
intel e6550 2.3 1333fsb 4mb cache @ Frys B&M for $179 + Tax - [H]ard|Forum
E6550 "G0" testing 3.6GHz w/ 1.29Vcore, 3.8GHz w/ 1.35Vcore Low Volts, High Clocks! - XtremeSystems Forums
A newer thread that is showing more recent overclocking of the e6550.
intel e6550 2.3 1333fsb 4mb cache @ Frys B&M for $179 + Tax - [H]ard|Forum