Took me a few to figure out how to do the update but I got it eventually. I personally don't see anything yet that is different but then again I usually play custom games so it may not affect me.

Mac Instructions

Open the .dmg and go-to

Show Package Contents - Contents - Resources - CivIVPatch.pkg

Copy/Paste the CivIVPatch file, open and run


I don't know yet what this update did but my game works fine so far.