if all the governments of all the world joint hands together to banned bitcoins ,then only would bitcoin can come to an end.otherwise it is not gonna happen no where soon. because of its decentralization and no technology could beat because it is the first of its kind.
Even they will do this so, still bitcoin people will keep on doing transactions again and again. The only situation that bitcoin will possibly die is there are no more potential investors that has interest on investing with it. And when that happens then the whole bitcoin economy will be dead very soon because of no incoming transactions and as well interest.