For specific questions about your network, and next steps, I suggest that you contact your account manager. I agree that the timing was not good for you, and I am sorry that this decision left you in a tough spot.
Cisco will continue to support the P3 base stations for the contracted period, in most cases 5 years after the end-of-life effective date. All customers will be given a last chance to buy additional base stations as spares or for finishing out an agreed upgrade or deployment once the P3 end of life is announced. We will continue to resolve issues and provide fixes for technical problems, but will not be developing new features or or releasing new WIMAX products.
Since you are upgrading from TD-SCMA to WIMAX, I can infer that you have installed a Cisco ASN-GWY. The Cisco ASN-GWY will support third party base stations through the open R6 interface, which has been tested with several other vendors. Alvarion is one that I know for sure has completed the testing, and they support the same three frequences that the Navini P3 supports. I am not sure about Motorola or Samsung. This will give you a path to migrate to other BS vendors in the future, and to find other sources of WIMAX CPE devices.
I am very sorry for your inconvienience - this was not the outcome we were hoping for back in 2007.