Isn't that out of scope of the discussion? Valve doesn't provide the online game capabilities of title and cannot guarantee you will be able to play online to all sort of old titles whose published shut down the servers.
It’s within the scope of the discussion. Nintendo should centralize its games into a single universal platform like Steam. Now that Valve has a successful handheld console it’s even more relevant than ever.
I think most nintendo users are kids and most of the games are given as gift and purchased in cartridges anyway. And people want to be able to buy and sell their games second hand. The nintendo network really is about online gaming in the context of the nintendo DS products.