While I’m not a Mac user myself, we do have a few clients that use them and are on BPOS in it’s currently limited form. This posting & interview over at the Microsoft Online Services Team blog answers a great question for those Mac users about the OCS client. http://blogs.technet.com/b/msonline/archive/2010/06/02/mac-and-microsoft-online-services.aspx
Service descriptions for Microsoft Online Services (standard)
Microsoft last week released updated service descriptions for Microsoft Online Services which consolidate all of the relevant information into a few easy downloads. You can get access to these documents here: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=c60c0af0-10cc-4b11-bcef-b989c1f168b0