I don't have a PlayBook, but on earlier BlackBerry devices such as the 9650 running OS5, a security wipe does not change the OS load. I don't understand why it would on the PlayBook. To restore to the factory OS would require that OS to be available to the loader after the wipe.
@lund - Yes indeed. My company has been testing the Playbook for a few weeks now. Each time we give it to a new tester we wipe it and have to go through the entire process again. it's time consuming to say the least. Since we don't have Wi-Fi it's even worse. I'd prefer to bypass the Wi-Fi and have the ability to plug in the PLaybook to a computer and update/register the Playbook, and push corporate policy down at the same time.