I was able to get First Strike to work with the Mac version of BF2142.

First acquire the mod. It comes as a Windows Installer so you'll have to have access to a Windows machine until a Mac version can be made. The installer just decompresses a bunch of files to the BF2142 mods directory. You don't need a Windows version of 2142 to run the installer, just point it at a directory and it will decompress itself there. The installer creates a FirstStrike directory. Take this directory to your Mac.

Now, do a "Show Package Contents" on Battlefield 2142.app. Navigate to "Contents/Resources". Do another "Show Package Contents" on the Battlefield 2142.app found there. Navigate to "Contents/Resources/transgaming/c_drive/Program Files/Electronic Arts/Battlefield 2142/mods". Drop the FirstStrike folder in there.

Run BF2142 as normal. Login. Select a soldier or create a new one. From the Overview screen, select "Community" from the "Welcome to Duty" pane. Select "Custom Games". First Strike should appear as one of the custom games available. Select it and click "Launch". BF2142 will restart.

Enjoy your Star Wars goodness. And may the Force be with you, always.

It would be nicer if the mod was available as a simple .zip so that Mac folks could just drop it in the mods directory and be done with it.  Would this be possible?  I'm not sure about the hosting and redistribution issues.  I could just create a torrent of it, but I think that'd be going around the First Strike team.  Maybe Macgamefiles.com could be persuaded to host it.  Perhaps a Mac installer could be made?

Anyway, great work.  Many thanks to the team.

- Jasen.