Testflight seems to be grabbing UDID's to identify users. You still need to get UDIDs in your provisioning profiles though. It'll make beta testing harder since users will have to use itunes to get their UUID. I'd love it if Apple would let users see their UUID and email it.
They make it so difficult in fact that just yesterday i got a screenshot of a UDID instead of the text because apple makes it look like you cant cut/paste the thing. Sooo frustrating.
