Sony just announced VIA Twitter that they will be giving away 400 beta code for Journey. All what you need to do is reply to their question and hope to be selected among the 400 chosen.
“Win 1 of 400 Journey beta codes! @ reply your best co-op experience by 5:15pm Pacific, add #PSNJourney. N. America only, winners are random”
Visit their twitter for more details: //twitter.com/#!/PlayStation