I certainly think there would be a place for them to use mobile as an idea factory. Much of what Nintendo devs apparently love to do is experiment with new gameplay mechanics, then build up entire major franchise games around them (Link Between Worlds being top-down due to the wall-merge mechanic, for instance). A few small mobile development teams, attached to the EAD groups, could let Nintendo work in a low-risk, high-exposure environment, creating small new IPs focused around any unique gameplay mechanic (gimmick, if we want to call it that) and being able to gauge consumer reactions so that they can know if it's really a good idea to base the entire next Mario game around "X".
Low-end virtual console games might have to go out to mobile just as a market inevitability. Such games, like the original SMB, are going to be pirated on those platforms en masse inevitably, so you might as well have them there legitimately to at least make some money off of that consumer desire. The further up-market the game, the less need there is to put it outside your eShop environment, though.
I agree that their next handheld should be Android-integrated. Solves Nintendo's infrastructure problems in one go and they get to keep hardware control, plus letting them tap into all low-end Western 3rd party support (which is pretty much all mobile now).
Monster Hunter: pissing me off since 2010.
