It'll last a month maximum because they job him out EVERY FUCKING WEEK and he has no credibility at all. So if they even put the belt on him (which I'm doubting atm), I expect them to complain that he's 'not over', which is 100% their fault, and then send him back to the midcard. It's a massive shame because he's one of the most talented guys on the roster and deserves much better. If booked right he could be a star but they don't seem to be willing to go through with a proper push, it's so half-hearted.
I would say about 3 months for his first real reign. Any shorter than that would be a waste of the MITB but I don't believe his current gimmick has the legs to remain fresh as a champion for much longer than that.
It all depends on how well they build him up. He has great ring skills and has good mic skills for the most part. He also has Vickie. With her, he can maintain a WHC reign for quite a while.
He has beaten most of whom you have named. Sometimes with help from Vickie, and other times without. With Vickie at his side, he can hold the title for quite a while.
2. CM Punk
1. Jeff Hardy
Not removing until
[x] Del Rio loses WWE title (NOC 9/18/2011)
[x] Mark Henry gets his ass kicked (Friday Night Smackdown 10/7/2011)
[X] CM Punk wins WWE Title again (Survivor Series 11/20/2011)
 Morrison returns to the WWE
[x] Santino Marella loses US Title(Summerslam 8/19/2012)
 Orton wins the WWE/World title
[x] Ziggler loses the US title (TLC 12/18/2011)
 Kharma Returns to WWE
[x] Sheamus wins the world/WWE title (Wrestlemania 28 4/1/2012)
At the very most, a few months, like Bryan's reign. With the likes of Sheamus, Del Rio, Orton on Smackdown, he'll likely only hold it a month or two. Guys like Ziggler and Bryan will never be the top stars, they'll only be the filler main-eventers. Guys like Sheamus, Cena, Punk, Orton, Del Rio, are the talent that WWE truly value, and they're the ones who get the long, established reigns with the belt.
My bet is that he wins the belt at TLC, Ryback wins the Rumble and kicks the shit out of Ziggler at Mania in about 5 minutes. So I'll say December 16'th to April 7'th, roughly 4 months, just a little under, which is WAY too long for somebody as horrible as him. He certainly won't be booked any better than he is now, and he'll lose every time that the title isn't on the line, because like Bryan, he's merely the placeholder for the pet project.
Given Ziggler's booking under normal circumstances I'd say a week to a month, tops, but with WrestleMania around the corner, they'll want people like Sheamus and Orton in bigger programs and Ryback needs a jobber he can steamroll over, they won't want him beating Sheamus.
112 - Civil War Trailer (& differences from the comic)
Huge week for Marvel with the release of the first Captain America: Civil War trailer! We also talk Fantastic Four 2 being cancelled, Guardians Of The Galaxy 2 rumours, Alien: Covenant, Legends of Tomorrow and Tom Cruise joining The Mummy reboot.