using a CD, DVD, or other optical-based medium is much more favorable to a solid state cartridge for a number of reasons. first, the production cost is dramatically lower. consider a 650 MB CD compared to 512 MB of RAM, or a single-sided 4 GB DVDR compared to that amount of RAM!!! there is no comparison. for that reason the space available on nintendos game cartridges (gameboy games, N64...) has been severly limited - allowing for more space on the cartridge means increasing the amount of memory on it, which means dramatically increasing the cost of each game. it's just not worth it, otherwise game developers would have to charge a lot more for games or would have to take a lot less profit. this, then translates to a severe limitation on game development. games of all forms, whether on consoles or computers, grow in size. a cutting edge game ten years ago could fit on a 3.5" floppy disk. now some require more than one DVD. if game developers are limited by the space of a solid state cartridge, they will be forced to sacrifice aspects of game play such as graphic quality/detail, sound quality, and the overall completeness of the game (do you think they could fit the entire story of a newer FF game onto a few megabytes of RAM?). this is one of the reasons why the N64 lost so many game developers to the PSone - cartridges are just too limited. sure, the cartridges will work fine for the type of games nintendo has been putting out for gameboy for the last 10, 15 years.. but to stay competetive they're going to need to give their new handheld some balls. the PSP will be able to play GT4, for christ's sake.

while we don't know FINAL specs of each unit, we already do know that the PSP will outperform the gameboy DS by a sizeable margin. the PSP is quoted as being a little more powerful than a PS2, and the gameboy DS is quoted as being a little more powerful than an N64. you do the math.

supposedly the gameboy DS isn't a replacement for the gameboy advance, but sort of a side step. they've said that their intention is to develop one or more separate handheld devices, so we can only hope that they'll release something else by the time the PSP comes out that can truely compete. until then, i think sony's going to whip nintendo's ass again.

as for the quality and quantity of games available for each console, the PS2 already has the most number of titles available, and most would argue that they have the better quality games too. nintendo always tends toward more family/kid oriented games, whereas sony aims for more adolescent/adult games. while the quality of these games is subjective, PS2 still has the market cornered. game cube does have superior hardware, so i think the games play a huge role in sony's success