I suppose a lot of people who like to try and predict the next big thing would try and guess what the precursors are. For example where would you be looking now for the equivalent of a camera OS that would end up being Android years later? That was at the tail end of the period where consumer compact cameras were a big thing (before they were bundled into phones), so it could be that there's a path of evolution from smartphones to the next big thing, but I wouldn't want to place bets especially if you're trying to judge whether there's an audience for it.