Yes, it was said that he will join PKR but what was never mentioned is when exactly, except I was told that it had to be somewhere in June. A friend of mine, who went with him to Penanti did told to myself and a few friends something similar what is mentioned in The Malaysian Insider:
Strangers walked up to him and urged him to sever his links with Barisan Nasional (BN). But until a week ago, he felt that he did not want to submit himself to the cut throat world of party politics, appreciating that PKR politics may be as distasteful to him as the shenanigans in Umno.
As a compromise, he decided that he would set up a brains trust of prominent Malaysians and provide intellectual input for PR. This unit would be funded by PKR-DAP-PAS and would help firm up a common platform for the Opposition.
Zaid told friends that he was concerned that PR was drifting. He believed that a better Malaysia is only possible with a strong alternative to BN. He briefed Anwar on his idea of helming this think tank and received the latter’s approval.