While LaFell seems to be the #2 choice for now, he might need to continue to improve to stay there. I think the ones behind him are hungry for chances, and Murphy hasn't had the acclimation time yet to show his potential.
I think you are right about LaFell being pushed. While Brandon has a knack for big catches in big moments, last year there were long stretches of games when he would disappear. Murphy looks like a nice fit in this offense, and Pilares should be a really good YAC receiver.
Gettis will remain a mystery until he gets some actual on-the-field action.