Pageau tries really really hard, all the time. He is small. He has the hands of angels and doesn't dangle them around like a show-off. At its core, Spezza being dethroned from the 1c position by Pageau isn't just likely -- its unavoidable and necessary.
The first point stands in contradistinction to most of the players that surround Pageau. As many astute observers have pointed out on the team 1200 over the years, Spezza just doesn't seem to try very hard, at least relative to players like Neil, Kassian, Volchenkov, Phillips, etc. Had Spezza the compete level, the "inner fire" if you will, of Pageau, this changing of the guard may not be so inevitable. He does not, so Spezza may as well turn the captaincy over to Pageau tomorrow. He is the real leader of this hockey team. Ask Mika where a simply Swedish level of effort got him and he will tell you: the discotheque in Binghamton, NY. Ask anyone and they will tell you: "J.G. Pageau is the future of the Ottawa Senators, and the reason they will one day win the Stanley Cup."
The next point that should make it clear Pageau is on the path to being Ottawa's #1 centre is his size. Ask any Adnan and he will tell you: "you can't teach small." Conacher, Pageau, and I don't know... maybe Tiny Tim? This will be Ottawa's next Pizza Line ("hot pockets?") and it will directly result in a cup. With a top PP unit of Conacher, Pageau, Tiny Tim, Karlsson, and Bennoit (he will have to be brought back for his size...), we will simply be unstoppable, because the simple truth of the matter is that small players are harder to find on the ice. People always talk about smaller ice surfaces and how the rink can feel really small with so many big players on the ice, but do you know who doesn't talk about that? J.G. Pageau. He is tiny, which gives him the undeniable physical advantage of being able to sneak and dart between the clumsy, larger players on the rink (i.e. Spezza).
The final point is that Pageau has gorgeous hands and doesn't use them like that darned Spezza guy. Spezza only ever does high-risk, zero-reward, behind-the-back passes to the other team. Anyone calling into a radio station can verify this statistically sound information. Pageau uses his damned-talented Gatineau hands to cause turnovers, make plays, and score hat-tricks. Once everyone else sees what I see, it will only be a matter of time before J.G. Pageau is the new face of the franchise, the new captain of the Ottawa Senators, and the first line centre that Spezza has always failed to become.
Three-to-Five years? Whatever -- this can happen whenever everyone is ready to wake up and smell the coffee!