PS2 had ~20 million units in consumers homes before GC and X360 launched. PS3 not only doesn't have a near 20 million unit lead, it's behind by 7 million (X360) and 11.17 million.
I only bring this up because a console with a 20 million unit head start will easily continue to out gain the competition but a console that must play catch up will in no way shape or form have sales on the level of the first console.
The rEVOLution is not being televised