Sony are looking for willing guinea pigs to test out the next big system software update which is coming to PlayStation 4. You’ll get to try out the new features before anyone else, although this is a beta so somethings may not work correctly.
You will need to be the master account holder on the PlayStation 4, and if it all goes a bit wonky you can roll back to the previous version of the software. If you in Europe and would like to sign up then follow this link.
Source: PS Blog