Those who were lucky enough to have been picked to checkout a preview of the new Xbox Live Dashboard, can do so now because it is up.
This is according to Engadget.
Dunno if this is the same in Europe or not, but give it a go anyway.
Update 2: Apparently, Microsoft has revealed that those who have signed up for the public preview should receive the update this coming Monday. All you have to do is sign up and hope you get picked, but there are loads of spots available. Thanks, D'toid .