He is only 24, and already a solid starter. Depending on the definition of rising star, he will be a player at least like Parker in the Spurs.
Here's the link (basketball-reference.com): http://bkref.com/tiny/QBo2d Nash is already the best (albeit, oldest) offensive player of the three. Far better shooter and distributor, but a bit turnover happy. His BLK% showing his lack of defensive athleticism. Was a bit surprised that he completes more FT/36 than Billups in his fifth season.
I see Lowry becoming a Rondo-esque player. Not a superstar, but all-star worthy. EDIT: Tony Parker is a way better comparison.
Lowry is a huge mystery to me everyday. He defies logic on players. I keep feeling he will come back down to Earth. He never does though. He is playing at allstar level right now. So for now he is already allstar level to me.
Lowry is a rare combination of talents and guts. Dude is a just a gamer. I guarantee you that if you are the opposing pg, you dread playing against Lowry because you are going to get in-your-face defense and will have to play defense yourself. Morey definitely kept the right pg.