Having services virtualized into cloud does not take away nor decrease the need for service monitoring and management. Viceversa they are becoming even more important as cloud enviroments usually increase the ammount of external vendors operating around your infrastructure.
One way to tackle these challenges is to re-engineering of issue management. Escalation processes most propably need to be renewed and you need to clarify roles and responsibilities of your vendors to match new situation. Most important thing is to secure proper interaction between vendors.