If you haven't signed up for the beta yet, you can do so (and get automatic access) simply by registering on the official website. In addition, veterans of the closed beta test (which powered down last night) will not have their accounts wiped for the open beta period. Finally, Massively readers who have previously received beta keys are eligible to continue participating.
New to the online racing scene? Be sure to check out our Need For Speed World coverage from E3.