Wow that site is enraging. I need to find whatever joystiq employee had the bright idea of starting "-fanboy.com" sites and strangle that person.
At any rate, the "loss" of Kawashima is not going to matter, because DS already has the Brain Age. Whatever Sony comes up with will just look like an attempt to be as cool as Nintendo.
Just like Killer Instinct was an attempt to be as cool as Mortal Kombat, Eternal Darkness was an attempt to be as cool as Resident Evil, and Metal Gear Solid: Twin Snakes was an attempt to be as cool as Metal Gear Solid 2. I'm not saying which of those games is better or worse than the other, I'm saying that copying popular ideas is not the best way to change the image/popularity of your product.