The scheme, dubbed "Nintendo Spot," is currently in a trial period, and will give DS owners access to free downloads featuring the latest "McDonalds news" (this just in: you need to learn to cook for yourself), nutritional information, and menus, as well as actual news, weather reports, horoscopes, a Brain Training demo, and hotel/restaurant guides for Tokyo (though we assume that guides to rival restaurants won't appear in McDonalds). The trial ends on June 30th in McDonalds, and on December 28th at the railway stations.
Incidentally, our machine translation is picking up something about a "downloadable gift" related to Pokémon Diamond and Pearl. Here's hoping the service heads west so we can find out more. While you wait with us, make the jump for a look at Ronald McDonald's offspring as perceived through the eyes of Japanese advertising executives (warning: slightly NSFW).
Gallery: Nintendo Spot download service