So I must be missing something big here, because it seems that this should not be an issue in 2009. Susan is fully on a Mac using the iCal app. When she sends me an invite, it shows up in Outlook on my end sort of looking like one, but when I click on the attached .ics file, the Accept, Reject, etc buttons are greyed out (for those of you wanting details, this is Outlook 2007, Service Pack 2 running under Parallels on a Mac). I did a bunch of searching around without finding an easy solution....
