Just for clarification, this topic isn't about adding Mac support. I'm aware you working on that in addition to Linux support. This is about adding the cosmetic enhancments the old Mac port of System Shock had (specifically the redbook audio and high res UI elements) to EE. Enhanced Edition just doesn't feel "Enhanced" without these components. Considering that the modding community has already hacked a high res texture pack for the old DOS edition,
I'd say the UI elements is the easy part. I don't know how you'd add the CD tracks. I'd also recomend adding an option to disable both in the settings for those whom find the DOS assets more nostalgic.

Also, I know the DOS/Classic Editon is included just because and not many actually play it, but do you think you could implment GUS support? Looking Glass promissed a patch but failed to deliver for the CD editon, and the "official" GUS AIL3 patches glitch out and stop playing on certain levels. This would be great for those whom had GUS cards and want a trip down memory lane.

doing anything with the old versions is not viable anymore - any future update efforts will most likely be focused on a proper windows port of the game.

What do you mean, I thought EE was native (beside the included classic edition)?

Well I do remember reading that SS:EE is based on, SystemShock.org user, Malba Tahan's slink; not sure if that's true though. Is he one of the devs they hired for EE, because I don't see him on SystemShock.org anymore?