Yes he does deserve the World Title, and he'll get it this Sunday. He won't "main event" though, he'll be a transitional Champion that falls back into the midcard when he loses the belt at Rumble or Chamber.
I'm hoping he'll grow into a Jericho type role in the company and get many many World Titles. I'm starting to fear he'll end up in a more Christian type role though, his booking is HIDEOUS.
I realise where they're going and that WWE will push Roman Reigns straight to the top. However for me, Dean Ambrose is by far the most talented in that group and I think eventually if they just give him the spotlight then he's going to shine. As soon as he touches a mic everyone else can just sit down as he's magic on it. So It remains to be seen, I think they're all talented but to me Dean was the star of that group. I think Roman looks like the star of that group but I don't think he's nearly as talented as Dean.