Never on 21 September 2014
Mario maker could do a lot for the system if done right. Like flipnote studio did for the dsi.
I'm personally far more interested in investing my time into making Mario levels than I ever was for little big planet. Don't want to be negative towards little big planet but it doesn't have anywhere like the tight controls and mechanics of a Mario game.
Assuming Mario Makers editor is good and flexible I don't think there's any competition.
