As far I see, for access to the BETA in general you still require a BETA application at least for Playstation 3 testing, as it states in the FAQ for Playstation testing that testers are required to apply for both to gain access to either-or.

Phase 3 is still technically 'Closed Beta' even if the NDA is lifted.
Phase 4 is 'Open Beta' where anyone and everyone can hop it, if you haven't filled it in, its safer to do so.