Whatever it is I hope its viewable by friends too, also make the book thing that records how many times you've played a game and how long and average play time etc. I love that shit for some reason, I don't know why but I like seeing what my friends ones are like too.
Don't have much hope for either though to be honest, doesn't seem like a priority to Nintendo so prolly just be a 'do it if you want' thing in game only.
While I like Compys I think something Nintendo related would be MUCH cooler. Stars or coins something, its so easy to design.