That's what i thought at the start until i had my training in CRM 4.0
two weeks ago, the instructor confirmed that the outlook crm client 3.0
should still function as normal after the server upgrade to 4.0 without
having to upgrade the outlook client as the crm 3.0 web service is not
removed when upgrading the server from 3.0 to 4.0!!
MBSS, MCNPS, MCTS