In my opinion, even though the PS3 is a fantastic console, the amount of PS3 consoles sold is very...disappointing, considering that it's backed up by the "Playstation" and "Sony" brands. And to compare it to the GameCube...wow. There is a difference when one says "The PS3 is on par with the PS2" than saying "The PS3 is on par with...the GameCube?" Not trying to bash the GameCube, as I loved this console more than the PS2. but I will be honest: to use it as a comparison is pretty unfortunate.
I agree that the PSP is doing very good, considering it's competing with Nintendo and it's DS. But the PS3, being in third place...just reminds me of what happened to Nintendo with the N64.
The fault here is Sony themselves, I believe.