Japan is not gonna forget about the PS3, make no mistake.

[HappySqurriel]

If you take a look at the following chart you will notice that at a similar point in its life the PSP had sold at (about) 2/3 the rate of the PS2, and at about twice the rate of the PS3:

http://vgchartz.com/hwlaunch.php?cons1=PS2&reg1=Japan&cons2=PS3&reg2=Japan&cons3=PSP&reg3=Japan&weeks=90

This means that the PSP was never really selling that badly, and a fairly large boost (in terms of console sales) of 50% could boost the PSP to the sales rate of a console like the PS2 ... To get to a similar level, the PS3 would have to see a 200% increase in average sales which is not (really) plausable.