I really have little doubt that the dragons are tied to Akatosh/Alduin, everything seems to point to Alduin playing a major role in Skyrim's story, presumably as the main antagonist, and it also seems that dragons were gone from the world and are only now returning to cause havoc, it seems to me like it would be an unlikely coincidence if dragons returning just happened to proceed Alduin's efforts to eat the world. Though even if it turned out that our assumption that dragons are connected to Alduin is wrong, the truth could turn out to be just as interesting, if not more so. It seems to me that it's pretty clear that Bethesda is putting a lot of work into their dragons, I mean, they even created a full language for them, they never did that for Daedra or the Sixth House, I'd say Bethesda is probably trying hard to ensure that people aren't dissappointed in their dragons.
This post made me think... were the cliffracers more powerful than dragons? If so, what would be the next rank of awesomeness? Maybe saint Jiub, he`s the guy who killed all cliffracers in Morrowind.
Actually, it isn't said that Saint Jiub killed all the cliffracers, the rumors say he drove them from Vvardenfell, which says, at least to me, that he did not kill them, not all of them, he just forced them to migrate to some other place, where? I don't know, and it's certainly possible that they couldn't survive wherever they were driven to, but who knows, maybe they not only survived, but as a result of Jiub's driving them away from Vvardenfell, they were actually able to avoid the eruption of Red Mountain and thus survived where other native species died
Regardless, though, obviously, an individual cliffracer is not stronger than a dragon, but they wouldn't need to be, they're far more numerous, and perhaps what happened is that cliffracers and dragons are the same things, and since cliffracers were more numerous than dragons they ended up eating all the dragons' food, thus keeping them from surviving in Vvardenfell, that's how I'd guess cliffracers might end up driving dragons out, anyway.