No one's droppable haven't you been reading the Cafe? You'll be taunted with "OMG, some noob dropped Liriano" in one of the dumb drop posts.
I'm still holding him in my keeper, but I wouldn't pick him up if he was dropped in my other leagues, until he shows some signs of life. One reason is that Manny is using up my bench room,. I think the dividing line is how deep is your league and how much bench room do you have? There should always be room for one prospect\sleeper\potential breakout on most benches. Mine's already filled with some druggy.
Of course what do I know I dropped Nolasco.