Does a Mac work with SBS2008

Not completely everything...
OWA, yes, but not the enhanced version as that requires ActiveX which is not supported on anything other than IE for windows
Remote Access, yes, via VPN and some access to RWW
Outlook Anywhere, not sure - MAYBE with 2011, not earlier versions.
Data Shares - When connected via VPN (or on the LAN)

You could run a Windows VM in Parallels or setup a PC in the office for people to connect to via RDP (once on a VPN connection).  The Windows VM would have full Windows access.

Just curious, how do others who are looking for the same setup that I am requesting, accomplish this with Macs?  Or do they just dump them and go Windows?

yes it does, check here for solution

http://www.chicagotech.net/netforums/viewtopic.php?t=4578&sid=85c5f48e8552283becfa356c9c34096

This thread talks about a data share from SBS2008 but doesn't cover OWA or Outlook Mac compatibility with SBS2008.

My essential question is, 'will a Mac workstation do everything a Windows workstation can'.  This includes OWA, Outlook Anywhere, data shares and compatibility.

Thanks for the info on the connectivity issue regarding the packets however.

Apple does not Macs for businesses (in my opinion) - they don't allow you to install their server version of MacOS on a true server with appropriate redundancies (they killed their server line this past January), Macs cannot be controlled through Group Policy (there may be some management one could do with a Mac Server, but Apple has little in the way of ability for administrators to manage the Mac.).

Macs can be used to access data on network servers (windows servers) when on the local domain but your question focuses on REMOTE usage and that requires a VPN for most tasks.  Again, OWA works - just not the one you get with IE - it's the same problem Firefox, Opera, Chrome, Safari all have on the PC - they don't support ActiveX.  

As I stated in my comment, YES to most things, just not as easily as Windows has made it (Outlook Anywhere is new and I've not used Outlook on the Mac which is why I said I don't know).

Great answer.  The customer also has Windows laptops and would consider using them, which, after this discussion I think I will lean towards pushing them to use.