IMPORTANT YOUR DEVICE UDID SHOULD BE REGISTERED BEFORE FLASHING.WWDC is underway, and lot's of exciting stuff announced for iOS5.
As a geek I took it upon myself to look for the beta firmware, and get UDID registration (thank you friend! I will keep him or her anonymous) done
Just finished flashing to iOS5 beta 1, so I guess I am typing this out to pass the time as my device restores.
IMPORTANT YOUR DEVICE UDID SHOULD BE REGISTERED BEFORE FLASHING.