I'm also surprised the PSP has only sold 11 million units of software but I once had a PSP myself and never even bought one software title and one of my children only ever bought GTA before we sold both of them.

Ran some more numbers. Only could use America and Japan since Europe didn't have software listings.

For NA + Japan

DS Hardware =  28,165,908
DS Software =  174,292,641
DS Attach Rate =  6.19

PSP Hardware =  13,709,944
PSP Software =  51,634,767
PSP Attach Rate =  3.77

 UMD honestly isnt a complete failure as movies are still being made for it. It has to be selliing decently otherwise no other studio but Sony would be releasing movies for it which isnt the case. Remember we dont hear this movie is being released on DVD & VHS anymore its DVD & UMD or HD-Format & DVD with a picture of the UMD copy just not mentioned. Basically UMD has taken the VHS part of commercials.  

Sounds about right - I have more than 10 DS games (and probably another 5 coming this year...). But then my house does have 5(?) DS/DS Lites - starting to lose count :P

...

I think Sony is satisfied with the PSP. They have given up "winning" this gen, and are focusing on just making some money - and helping the PS3 get started. They still have GT Mobile & some other huge titles coming out, so there is plenty of life left in the PSP. The PSP *could* end up outselling the DS - but only if Sony keeps it going for double the DS lifespan (all unlikely).

There is also the chance of a 'new' DS skew coming out (I still think there will be the new PSP at Xmas). DS Digital (or something) with the ability to download games OTA ("over the air").

One more week till I get a DS! Advance Wars Dual Strike here I come!

It's amazing how this handheld gen is expanding the gaming market. The DS has just exploded into the public sphere, increasing the amount of Nintendo handheld penetration, at the same time as a new entrent has managed 20+million in sales.

That said, the PSP isn't doing very well. Not compared to the DS, not compared to Sony's expectations and sales predictions. But it's still got plenty of steam left in it. 

How about i put things simple:

The psp is doing good, the DS is doing better

Developpers are gonna make games for both systems although DS prob get more games

Both handhelds are succesful with DS doing better then expected and psp doing worse then expected

Everyone is happy (at least the gamers are), both psp and ds fans get what they want

No one knows futur but prob continue current trend 1/3 market share for psp and 2/3 for DS but the futur is anyones guess

Does that sum up everything?

Not really, because we don't really have a good idea of how much profit Sony is making. They had multiple price cuts. It's not clear whether Sony is making money off hardware sales and even if they are it's probably minimal. It's hard to tell how well software is doing since there are so few million sellers. 

The DS on the other hand has had fewer price cuts. Plus most experts have agreed they are making a profit of hardware sales, even after the price cut. In addition they have a higher software attach rate further increasing the profit lead. To top it off, software development costs are lower as well. If that isn't enough, Nintendo has the best selling first party titles which further adds to profits. 

The PSP really has only had 1 price cut, which is the most recent one. The system debuted as a bundle for 250, and soon after the system was offered on its own for 199.

The software attach rate numbers are pretty interesting. If you just look at American sales, the PSP has a slightly higher attach rate of ~3.75 vs. ~3.60 for the DS. But Japan is just nuts! The attach rate there for the DS is over 8 games per system. Nintendo has sold 130,000,000 units of software in 2+years in Japan. In 7+ years, Sony sold 148,000,000 units. The DS' numbers are so ridiculous, I'm almost inclined to say this site's figures must be wrong, but I know very well that VGChartz is really accurate. Crazy.

FishyJoe, like jman8 says, there has only been 1 pricecut.  Either way, I think it would be hard for Sony not to be making money at this point, and there are a lot of good games coming out this year.  I think the PSP has been quite successful even if the DS has been a lot more successful, largely due to Japan just going nuts over it.