Check the I9000 dev section at XDA for updates on CM7 for the SGS. Codeworx and others are working hard at getting it prepared and no releases are happening until it is functional. Follow them on twitter as well if you use it.
From the sound of how things went down, and to be honest I stopped tracking it directly so I would not go crazy with the wait, the CyanogenMod guys that were hacking CM6.1 to SGS switched their efforts to using the Nexus S 2.3 as a starting point for CM7 instead.
As I understand it, this is more work than a port and we should not expect anything too quickly... thus I stopped watching every day.