yeah... they *do* advertise mac compatibility on their
http://www.discoverblackberry.com/di..._solutions.jsp page, but seeing how the product does exist and work in some very rare ideal circumstances (even if not consistently), i'd think a lawsuit would hold up.
however, if you do honestly feel that RIM or your mobile carrier misrepresented the phone's compatibility with your computer, i'd suggest complaining to your state's attorney general's office as a first step.