Messenger for Mac 6.0.3 has released to the web. Allow me to share one item for those of you aggressive enough to be playing with Office Communications Server 2007 - this is not the client for Mac allowing you to experience the new rich presence.
So what does and admin and end user do - well I suspect that the bulk of the folks using a Mac don't also use a PC so you simply make sure that you enable them for OCS and DO NOT ENABLE FOR ENHANCED PRESENCE.
But what if you are a PC user who has a Mac for testing or at home, what do you do? Well you stay with enhanced presence for the improvements and patiently wait. You can use Communication Web Access using IE or Safari on the Mac (this assumes the admin has updated the CWA server to the new 2007 version).
ps - I have just returned from my paternity leave and catching up, one big thing is that I have to rebuild my virtual machine environment.... again!