Well, it's official, PS2 is dropping down to $200US here in the states, within a few days. This could potentially throw a wrench in the gears for Xbox/Cube.
But still, all things point to XBox dropping to $200US (or less) as well (but it's still not confirmed until E3).
Interestingly enough, Nintendo said if the other two systems drop, they will bring the Cube down to $150US.