People are underestimating Subban, or perhaps over exaggerating his immaturity. He made great strides to do precisely what the team asked of him from last year to present day, even if I highly disagree with the ban on the triple low-five. The kid exudes confidence, swagger and leaves it all on the ice. That type of persona is infectious and invigorating. When your leader is pumped every game, you're pumped right along with him. Furthermore, I believe PK would take it upon himself all the more to be a respectable captain without losing the aforementioned characteristics.
Gionta will serve out the remainder of his time here as captain, and thereafter PK should definitely be the frontrunner to carry the torch.