Make it the biggest? Well first off, not Santino. He's one o those extended "flavors of the month." Boogeyman, Eugene, Hornswoggle, they were in the same boat. They all hd somthing awesome going. Not huge, but they were in the spotlight, even for a bit (not as much boogeyman) but Santino is the same. He only gets a reaction for his mic work, not his ring skills. I see nothing hugely memorable from him.
I can't really see Miz or Morrison passing one another anytime soon. Neither guy makes a good heal or face. They're just "cool people". No one hates them, and no one loves them. Cool, but bland, and that won't get them anywheres.
Kennedy... It's been said. The guy has Main Event all over himself, but he keeps having Karma bite him in the ass.
I picked Bourne, but I no longer know why. He's popular now, but for how long? He's still way to new to see anything long term with him. In a year, if he's got the spot he has now, it'll be doing better then half the roster, so props for that. But like Burchill and Burke, he might only be popular for the forseeable future before he's givin up on.
And why such a small list anyways? Theres alot of other guys that could be huge you never named.