Is there a way to make the Global address book the default address book for Outlook without having to touch every Client?   Also is there a way to make the Global address book for all new clients that we setup?

Hi

I'm not very clear your question. What client do you want to logon mailbox ?

For second question, maybe you can use GAL Segmentation:

http://technet.microsoft.com/en-us/library/hh529948(v=exchg.150).aspx