Wow you guys really have not actually looked at the DSi very much.
The part of the DSi that is region-locked is the store. Not the actual DS games. You could still buy any DS game from Japan and play it just fine on the DSi. The DSi store, just like every game store on every system, is region-locked. And yeah, there's the SD slot for any sort of workaround you want anyway.
And honestly, no, the GBA really isn't a popular system still. The US has literally zero new GBA games now. Even Japan has next to none. And losing support for GH: On Tour really isn't a bad thing because the game's terrible. And seriously, if you really want to play GBA stuff, just keep your DS. And hey, just wait for someone to build a GBA emulator for the DSi and just load it on your SD card. Now you're enjoying your "missing capability" and totally "sticking it to the man" at the same time. Games that use the GBA slot for expansion are few and far between.
The DSi also is NOT more expensive than the PSP. The Japanese PSP Slim is, at its lowest, $209 (the new series PSP's are $250). The DSi is the equivalent of $189. This is perfectly in keeping with the DSLite's pricing as well. When it comes out here, the DSi is expected to retail for $150, which would be $30 more than our Lite.
Also, there are PSP games that DO use the extra memory of the Slim. There are also games that force overclocking the PSP to run better, which on the original PSP, affects battery life quite a bit.
I also have no response for talking about Nintendo as though they aren't making games to cover everyone. In their first YEAR, they had nearly every major franchise covered. Now, they're pushing out into older franchises that haven't seen updates in almost a decade, getting other development houses to help develop many games that originated on handheld stuff, but now as full-scale console releases and literally every single one of their games works exactly as it should. I say this a lot but if you actually sit there and tell me that nearly every game you've played on the Wii sucks, you are either really bad at picking games in general, you suck at the game, or you're lying. I own no less than 12 games for the Wii and I wouldn't trade in any of them and there are tons more still to come that I want. 2009 alone has more for the Wii than any system so far.
Nintendo did NOT ever say they were going to shift focus only onto the "casual" crowd. Ever. What was said, was that they would split their resources to develop for all forms of gamer, and they have done exactly that. Looking at their lineup, they've already provided games for literally every style of person, from babies and retards (Wii Music) to the ridiculously "hardcore" (Fire Emblem) and like I said, nearly every major franchise has been represented.
Seriously, what do people need from them? It's ridiculous. Everyone creamed themselves over the DSLite, which was nothing more than a light upgrade and a slimming. The DSi is the same thing but with even more (I have no clue as to what the cameras are actually for though...although being able to take a picture of something, quick draw all over it and then upload it onto some site through the DSi's built-in browser is really neat) and now people shit bricks in anger for....some reason? It's not like they're really charging you much more for the stuff you don't want. The JP version is the same price the DSLite debuted at and the US version's only $30 more, which is almost all represented in the bigger and nicer screen.