Let me break this down for you. IF you install iOS 7 Beta 1 from an IPSW that you downloaded from the Internet, found on the sidewalk, OR got directly from the Apple developer website, upon installation the device will check with Apple's developer server and verify your UDID is on a registered developer's account. Until that verification is completed with Apple, you have a nice, shiny, expensive paperweight.
If you want to install 7 on a non registered device, be my guest... The reason I am replying in the first place is so that your misinformation does not brick someone's device that doesn't know better.
Enjoy the site.
You keep saying this but it hasn't been confirmed. People keep trying to tell you that iOS 6 betas didn't require UDID registration (I can confirm that). Apple may have decided they'd rather not have a bunch of bricked devices carried around by fanboys. Or maybe they'll reinstitute the UDID check this year. No one knows yet. (My guess is they won't.)