While this is a good sign for Dolph's career overall, you guys seem to be forgetting the PPV he's getting the shot on. Royal Rumble. In recent years, the Royal Rumble's been used to give midcarders a title shot they'll never win.
Take a look at some of the challengers for either heavyweight belt in the past 6 Rumbles.
Bob Holly (Lesnar '04)
Mark Henry (Angle '06)
Umaga (Cena '07)
Mr. Kennedy (Batista '07)
Jeff Hardy (Orton '08)
JBL (Cena '09)
None of these guys aside from JBL had ever been champion, none of these guys at the time (or ever) would you see in a Wrestlemania title match, and none of these guys won.
Well.. Holly, Henry, and JBL just look like lambs to the slaughter (JBL retired 3 months later for example), taking unimportant names out of the Rumble to challenge for the belt to give the champions something to do on the PPV. However, Umaga, Kennedy, and Hardy were all definite up and coming midcarders on the verge of the main event scene. Dolph Ziggler is definitely comparable to those 3.
Since 2000, the Royal Rumble has seen exactly two (2) title changes.
John Cena ('06) and Edge ('08)
Two guys who are undoubtedly Wrestlemania title match material.
Which is what it all comes down to, Wrestlemania. It's too close to Wrestlemania to put the belt on Dolph or many of the guys who challenged for it in the past. Especially with this year's Wrestlemania having a very cloudy title match picture. The rumored title matches are feuds that haven't even started yet, nor are atypical of Wrestlemania headliners and would be unfortunately underwhelming to the general fanbase. (Miz v Cena, Barrett v Taker, Orton v Punk, is what WZ has been reporting)
It's great that Dolph has been given a chance to showcase what he's got in a PPV world title match, he's been a solid worker who's had a very good year in the ring. Let's just remember history ain't exactly behind Dolph. It's a reward for a job well done, and a test for the semi-distant future.
Personally, I think Dolph's pretty good in the ring, but his name and general lack of mic skills/true charisma will prevent him from ever really being a main eventer. One of those can be fixed with a little effort, the other is going to take time and may never come.
And if Dolph's a career midcarder who puts on good or better matches, then it's not like he failed. Mr. Perfect and Ted DiBiase Sr. were both career midcarders, both are revered around these parts. It's all about perspective.