At TechEd 2013, we announced a new enhancement around VMs that are stopped from the Windows Azure Management Portal - Stopped VMs will no longer accumulate compute charges, because the fabric resource reservations that were previously maintained are now deallocated when VMs are stopped.
This is great news for some interesting "hybrid" cloud scenarios, such as:
• On-demand dev/lab/test VM environments in the Cloud
• "Bursty" load-balanced web applications
• Disaster Recovery fail-over scena