I'm not sure about this, but if you think about all the evidence maybe there's a possibility that Kojima will work with Sony and the thing could be announced at PSX.
We know that Kojima left Konami, even if the company is denying it, that picture of the farewell party is proof of this. We also recently knew that Donna Burke said that Kojima's new project will be revealed soon and the director is based in Tokyo. This is demonstrated by the fact that the contract between Kojima and Konami will expire at the end of this year, so it seems natural that we won't have to wait long to hear about Kojima's new works.
Last but not the least, Sony and Kojima always have had a great relationship and Kaz's company is one of the few that could give Kojima all the money and creative freedom he needs.
So I think there's a 50% probability that it might happen.
What do you guys think?