Now that Sony has said that devs can self publish for PS4, I'm betting that a lot more people will be interested in producing games for that platform.
What is the process for getting the SDK, documentation, and testing environment for a PS4?
Thus far, there is no indication that Sony's self-publishing option for the PlayStation 4 is actually an open publishing environment (like the PC). You still need to become a registered developer and that still involves being vetted and approved by Sony, licensing hardware, et cetera.
According to this press release:
You will note that the linked site details a four-step process to register, but notes that, before applying, the following requirements should be met:
The actual online application form asks for various other things an established company should have, as well as information about your development history and published titles, six-month product development plan, et cetera.