This is Nintendo's answer to the PSP. In a market where people are more attracted to "OMFG!!!111 IT SI TEH MOR POWERFUL!!!!11" than solid game design, putting up a 2d console against a 3d one would be suicide.
I haven't really been following either system (even though I regularily visit a DS website from when I used to have a GBA), so I can't really judge which will be better. If I were to buy one, I'd probably wait for the PSP then make a choice after that.
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Poop.