Currently they are undergoing closed beta phased, people who missed out the registration a while back will have to wait for open beta at a later date, probably late August as some of the others have mention.

Odd I didnt received any invite, do I have to register or do anything? I am using US PS+ (still active) and also have PS Vita.

Ah turns out I dont need the email for Beta Code. The beta is already in the store for me to download today (PS Plus user here).

Up me add as well for the party. I'll be around tonight as long as my kids doesnt crawl up onto me to grab the Vita .
PSN id Avacier83

Guys just follow the format provided by bro Ninja. Copy paste and add your own id to the list. Less hassle for him.

Dang have to press again in the middle, no wonder they keep changing even though I thought I got the matching correct