Is an Orion license included with an Acropolis subscription?

Yes, as of April 2013. Note that prior to April 2013, Acropolis and Orion were offered as distinctly-priced solutions, and an Orion license subscription was a prerequisite for an Acropolis subscription. Since it made no sense to separately purchase an Acropolis hosting subscription, Acropolis has been redefined (and correspondingly repriced) to include an Orion subscription. There is no net impact on the license subscription fees paid as a consequence of the redefinition.