The PSP launch has "created a frenzy of buyers"?
Anyway...I don't see (if this is indeed intentional) how Sony can benefit at all. Aside from some exclusives (and I do mean some since a lot of series are multiplatform now), the 360 and PS3 are basically clones of each other.
To launch a year late with only 500,000 units, especially when you're relying on the system to push your own DVD format, would be very stupid if it was on purpose.