The next major platform for AMD, socket M2, shall be a revised 940 pin socket. It will not support any current socket 940 processors and will be used for desktop processors, not strictly servers. The memory controller for Socket M2 will support DDR2, most likely DDR2 667.
AMD also has plans for another socket, named socket S1, built specifically for mobile processors. This new socket is being built specifically for ultra low power consuming mobile processors using Turion technology. AMD has proposed that these processors will use less than 7 watts of power consumption and will be availible in 2006. It is speculated these processors will also use a 65nm process, but that is not confirmed.
Socket S1 actually decreases the number of pins, using 683. This is obviously a sign that AMD will be decreasing the size and power consumption of the chip.