As long as you have the latest BIOS update, it should support the Katmai 550. The problem is whether or not it will support Coppermines due to their lower voltage.
If the latest BIOS does have support for Coppermines, but the board does not support the lower 1.65 volts required by them, you can manually set the voltage to 1.80 (the lowest voltage the older P2Bs support) and use an FC-PGA processor and slotket. This setup will work.