Ha, I see I got an automatic email with this information. Thanks!
Yes, this is because RAM, diskspace, CPU, and your IP continues to be reserved on the hypervisor.
If you want to power off a virtual server for an extended period of time and recover it later we recommend taking a snapshot of it, destroying it, and then creating a new virtual server from that snapshot when you are ready to use it again.
Everything will be preserved except for the IP which will change to whatever free available IP is next to be assigned.
You won't be notified about changes to this idea.