That video was pretty impressive. Initally when I read the OP's first thread, I thought "no way", but now I'm thinking that Santino could be a legit contender. Maybe not actually win the World Title, but he has the skills to be near the top of the card. A couple of things to consider:
If you watch the video, you can tell he can go in the ring. (Not that you can't tell that from what he does in his comedy role, but that video makes it more apparent.) He definitely has the skills. Nice moves, nice intensity. Again, you can see that even in his comedy role when he wrestles, but a lot of times it's tougher to see or take seriously in that role.
Yes, he's a little pudgy/not in the best shape right now, but his physique looked pretty good in the video, and if I remember correctly, he was in better shape when he won the IC belt from Umaga. So he could get back to that again, improve his body and lose the pudginess. Of course, he is on the smaller side, which would work against him. But Daniel Bryan is the World Champion right now, correct? Whatever people might think about that fact is one thing, but he has the belt. With Santino having a gimmick similar to the one in the video, is it that far of a stretch to think he could reach the top? Didn't he remind you a little of DB doing those rapid kicks? I think a gimmick like that would be believable on him despite his small stature because you can tell he has the skills legitimately. Again, I'm not saying he would actually win the title, but I really think he could be right near the top.
Lastly, as someone above mentioned, remember Sexual Chocolate? Mark Henry came back from one of the most ridiculous roles/storylines ever to win the belt and be one of the top heels. Granted, it was probably easier for him than it would be for Santino because of his size, but I think it could be done.
All this being said, he's obviously great in the comedy role as well.