So ... I just spent a lot of time finding out how to get a Beta key ... and here is what I found.
A recent edition of PCGamer comes with a beta key. It says so right on the cover.
Also... The Sony guys are serious twitter people. They give out a few every day. But the first person to redeem it gets the code. You would have to be watching at the time when they give it out.
Joshua Kriegshauser .... @autenil .... is who I got one from, just lucky timming on my part.
there is an official account .... @planetside2 ... this twitter account is giving out a couple a day.
There are several forum posts around the web that say if you ask on twitter... @planetside2 , will email you a key. There has to be some truth to this because I saw it a few different times. Let me know if anyone trys this.