The latest edition of Tyndale Tech has a useful overview of how Unicode fonts work, or otherwise, on Macs. While David Instone-Brewer’s comments and the resources he directs you to are helpful, others have have picked up the major issue that his piece raises, namely that at present, you cannot use Right to Left when using Unicode Hebrew in Word for Mac. Mark Goodacre presents this as "Mac Woes: while over at Deinde, the argument is for therefore abandoning Word altogether and going for either NeoOffice (Instone-Brewer’s solution) or Mellel (Deinde’s solution).
The problem for me is simply that I use EndNote. This doesn’t work with NeoOffice of Word (or Pages for that matter), and so Word is still the only option. I could transfer to Bookends and use Mellel, but as Danny recognizes, there is a great deal of relearning to do here.
Plus, despite the existence of Unicode, both T & T Clark International and Paternoster still ask for SPIonic.
So for the time being I think I will be sticking with Word + EndNote + Unicode whenever I don’t need to use Hebrew (which is most of the time).