@Louie
First, let's make sample size bigger to be more accurate. 2008 calendar year for instance, 3rd party software sales (i.e. not developed or published by Nintendo or Sony) according to VGChartz:
DS: 56,2M - 71.3% of total sales (America); 14,8M - 55,5% of total sales (Japan).
PSP: 12,6M - 72,2% of total sales (America); 8,2M - 91,8% of total sales (Japan).
In other words your speculation "While the DS sells more software most of the software sales are Nintendo games" absolutely not true for America and the same goes for any other market except for Japan. You made an assumption that former speculation is true "at least in Japan". Well, I'm not going to argue that. It it is true, that notably bigger part of DS software sales in Japan are Nintendo developed\published games if compared to rest of the world. This could mean one thing for sure - Nintendo is the biggest software publisher in the world (in Japan Nintendo position even more dominant, which could explain why 44,5% of DS software sales in Japan last year are Nintendo games), Nintendo games have high appeal to japanese public (at least some of them), obviously all Nintendo games are published on Nintendo systems - as a result a quite high percentage of 1st\2nd party game sales on Nintendo systems even on those, which are fully supported by 3rd parties, like DS. At the same time as you may see 1st party efforts on PSP are pretty much insignificant in Japan (~8,2%), this could mean two things or both: a) PSP didn't see any strong 1st party games for a while; b) there're no or very little 1st party games that appeal to japanese gamers.
My point here is... if 3rd parties have the biggest part of software sales on the system compared to rivals, this's doesn't direclty means that system is healthy. Absolute number are relevant. But again I'm not going to argue that DS software sales are down while PSP are up last year in Japan. Here's potentially could be a problem for Nintendo, but did Sony have something to threaten Nintendo in Japan? Because Sony definitely not able to threaten Nintendo anywhere outside Japan, no chance. Finally, back to the topic... most part of already announced and, I assume, games that still going to be announced this year on PSP have no or little appeal to japanese gamers (current line-up purely westernized), and those that do have one are unlikely will change anything even in Japan (do you remember, this year is the year of DQ9 in Japan? and I can't see that Japan will get FFXIII Agito this year).
If Sony is going to threaten Nintendo, they need to do this somewhere, where PSP position is stronger, i.e. in Japan (2nd selling system after all, well... there're two of them which are selling decently anyway ^_^ ). I dunno if they going to do this or not, or how successful they will be, but THIS line-up won't help.
