If a 360 slim came and sold like that, I would consider it a flop. However
1) The 360 slim wouldn't nearly be as dramatic of a change.
2) The PSPGo wasn't made to take the place of the 3000 like the 360 would be made to do.
3) The 360 Slim wouldn't rely on complete different methods of distribution.
4) The 360 slim wouldn't release at a higher price.
Overall, I think you're making a weak comparison.
4 ≈ One