Over on NeoGAF, user Atheerios, has spent some time looking into the leaked Nintendo Switch SDK and found some evidence of future features that are to be added. This includes the much requested "save data transfer". that allows you to transfer save data onto multiple consoles. The second, perhaps even more exciting is "guest login" which will allow you to link "a network service account" without creating a user, thus in theory allowing you to access say your character data for a particular game on a friend's console.
Naturally Nintendo could be hinting at features in the SDK are far out, and that may never come to fruition, but hopefully these features will soon be available on the Switch.