This worked on earlier Beta's. I have not tried it on RTM or later Beta's but it might still be OK.
After the aurora shows up on first boot after setup, hit Shift-F10 and a command prompt will show up. If not hit ALT+TAB to select it from the pop up. Type "taskmgr" and hit Enter. In the task manager, close "msoobe.exe" (End Process). Windows will either log off or reboot. You will then login as Administrator. You can then enable the true Administrator account and also disable the requirement for passwords (Go to run, and type Control Userpasswords2, and then go into Advanced/advanced/users.)