On CAG theres a large thread of Gamestops marking new PS2s are used. The PS2s collect dust at my Wal-Mart.
US wise I am going to call BS on the PS2 demand, considering Gamestop is pretty damn big and so is Wal-Mart.
PSP I am going to agree with. We have a hard time keeping PSPs in stock. I honestly think the PSP could have another good year or so in it, but that's just me.
Other countries? I have no idea.
It's just that simple.