Sony don't especially know how to support handhelds while Nintendo do know how to support consoles. - In short, it wouldn't make any difference to my Super DS but it would be lovely for Sony fans I suppose.
Also Nintendo are a long way from supporting smart-devices... Sony may be closer but only because it doesn't conflict with the PS4/5. Actually if Sony still wants a piece of the handheld pie they should really just start supporting the Super DS when it comes out.