Intel are not dropping it, there are just no new chipsets being made in the coming year for it. Its not expensive, the price is now within a few percent of the cost of DDR, it has higher bandwidth, but higher latency. The latency issue gets less the faster it runs, so 1066 Rambus, which is imminent, has lower latency.
Amd do not use it at present, but they do have a licence to use it if they so choose to. The XP is not designed for that amount of bandwidth, where the PIV is.