Galnet is not ICS - it's a hacked ICS framework over Gingerbread.
As to what will be needed for ICS on our device:
1) I9100 ICS to become official - until this happens, there is no kernel source for the leaks, and thus nothing that can be done to try and port it to our device. Once kernel source drops, the work for porting that release to I777 starts. Touchkeys should take a matter of hours or days - mainly due to whether that kernel source drops when I'm free or when I'm busy.
2) Audio routing issues fixed - this could prove to be highly problematic, as it's not within the open source kernel. On Gingerbread, the workaround for this was to disable Samsung Noise Reduction - this may or may not work on ICS, it's too early to know. If the audio routing issues prove insurmountable, we may need to wait for an I777-specific leak.
Either way - Our start gate is when I9100 ICS goes live AND kernel source is released (sometimes Samsung takes a few weeks to drop source for updates - see the Infuse as an example), right now Samsung is claiming March for that, and based on the progress of the XXLP* leaks, I think they are on track for that.