Jonathan Ponton has written up an excellent, detailed, step-by-step description of how to use Service Manager and Orchestrator together to automate the process of creating a new user in Office 365.  Read on!

http://seethruthecloud.com/using-system-center-2012-orchestrator-to-create-a-new-user-in-office-365-from-a-service-manager-service-request 

Very cool Jonathan. Thanks for sharing!