Intel has announced that it won’t be selling some of its famous CPUs, including the E6700, E6600, E6300 and X6800.
They simply reached their end of life cycle, and so have the E6420 and E6320. All these CPUs belong to the Merom Core 2 Duo generation, some with more, some with less cache. They reach end of life in end of January, but don't worry you should be able to buy them for at least a month or two.
They are being replaced with cooler and nicer 45nm Wolfdale generation E8xxx processors that are starting to ship at the same time. So long, you nice chips, you've served us well.