It's only selling well now because it's new. The momentum will die down. PSP has no chance against the DS... No chance...

@alex

Dont count the psp out yet..

I wonder what Sony's expectations were for the PSP when it was released?

With more of 20 millions of difference there is no way it can recover and take the lead.

Edit: 

joshmyersBV

Make use the PlayStation brand to take over the handheld market, make the UMD a mobile standar, sell tons of movies and kill nintendo taking away their handheld market...

I was in Yodobashi Kawasaki yesterday and there was a LOT of interest in the new PSP. Most of the peripherals were sold out (headphones, TV cables etc).

Also, MGS Portable Ops + was sold out too.

 Wait, you mean that Nintendo was the first company to come out with a "slim" version of a game machine (handheld or console)?

 *recalls a couple Sony game systems that had a "slim" version*

 Gameboy pocket was pre PSone.

But claiming that a hardware revision is copying Nintendo. Using that logic we could claim that every console maker is copying Magnavox who released the first ever console in 1972. 

 Atari 2600jr says hi

I don't know man? Sony still needs to sell like 27 million PSPs to catch up to the DS. PSP is selling well but not that well. It will do well but not as well as the DS. 

 It's not a copy in releasing a redesign.  If you are thinking that way then man you are already way off track.  If this is a copy it is a copy for market hype and advertising.  It's obvious Sony wants to reenact the success that DS had after a newer version of that handheld was released.  Thus they take similar aspects that the DS revision had and market it off with a similar name, ect and you have an exact replica of an event that occured previously on a competiting product.  With this in hoping that the same sales increase will happen and virtually feed off the same hype and good sales that the competitor had.  

This is most likely what Sony was thinking when they decided to redesign the PSP.  It was all about this copy of marketing and advertising to ultimately gain what the DS lite gained for Nintendo and its handheld generation.  I'm not saying it's wrong, unfair, cheap, or sly but I can say that that this redesign was under those precepts.  You see this happen a lot in the market.  Namely after you see a succesful series in a specific genre you'll then see "same games with new names" arise.  After Halo this happened a lot in the market.  I think Killzone is the most obvious as Sony simply stated that is what it was.  Can't get any easier.

For that same idea above you saw it after Nintenod released Brain Training.  Can't look in the Japan weekly sales without seeing market copies.  Saw it after Nintendo released Pokemon.  I think things like Digimon is a good example.  Not everything is a deliberate outright copy of what physically it is.  Mostly it's a copy to feed off the market hype surrounding what a previous and similar product has done.