Get yours here: Code: http://www.massively.com/2010/06/25/put-the-pedal-to-the-metal-with-some-need-for-speed-world-beta-k/
Hmm i think all the beta keys are gone. I tried like five times, each time getting a new beta key, and they all don't work.
That must be because everyone clicks and generates one at the same time perhaps. Also, these would work for all the platforms.