The reason it says Compatible with Intel P55 chips is 1) it meets the voltage requirements of 1.65V or less and 2) is a dual channel set. It will work on AM3 boards just like it does Intel.
This statement was a "big thing" when the new Intel chips came out with their voltage requirements. It showed which memory meant the requirements. Most memory is coming that way standard for DDR3, so no need for that reference. The Newegg descriptions just haven't been "updated" to remove.