DPHS stands for Dual Play HeatSink.  On the motherboard you will find it has holes drilled to support a Socket 775 or the new Socket 1156 heatsink on it.  This feature lets enthusiast take advantage of your old Socket 775 heatsink and use it on this board.

This feature is not available on the P55V (E650) or the H55V (E630) motherboards.