I guess I'm in the minority but of the 3 players mentioned Stewart has the best reason to leave. He's our best WR. He averaged 15 ypc and made the most memorable big catches of the season. He's a 1,200-1,500 yrd All-American receiver on a team with a throwing QB. I think he will surprise people in the NFL.
With the remaining two.....one needs to start looking for the ball in air to play in the NFL. It's not good enough to just 'be around' the WR. The other needs to learn that you can't start the play before your center snaps the ball. He'll get drafted high.....some team will have to adapt playcalling to 1st and 15's though.