Well, the question isn't who will win in Turkey. No, the question is which one of the Redbulls will win in Turkey.
Webber has the crown Jewel of Monaco under his belt and two on the bounce, momentum and lady luck are are sitting nice and comfortably on his shoulder. He now knows he can put a weekend together and come out top Dog. His supposed better team mate has been lackluster in the last two rounds and not challenged the older man. Formula One is as more about tuning a drivers head into racing winning, than giving him a car to do the job. Webber now believes he can do the job which is going to make him a hard man to beat.
Vettel is equal on points with the Ozzy, but has had no luck with a broken car for the last two races. This means you have to ask that if he'd had a pukka car would he have been pushing Webber harder. At Monaco, probably not as It's not a circuit he likes, but Turkey will give him more room to show what he can do. But if Webber is faster on day one however, Vettel will struggle.
The only driver i think can challenge these two is Alonso. I've been saying from the start that I think this is going to be Alonso's year. Turkey is going to be a race that he has to take to the Redbulls. They will be faster than him, so he'll have to stay in touch to profit from any mistakes the other two make. If he makes another mistake like the one in Monaco he's going to make the job harder than it already is.
Also bare in mind also that Massa has always gone well here. He's not the sharp driver he was last year, but he can still get the job done when on comfortable territory. The Ferrari is fast, it just needs to be driven fast.
As to the rest, I don't think Kubica will be as fast as he was in Monaco, the Renault isn't as fast as the rest of the pack in a straight line and spanking the car won't make it go any faster here. The McLaren boys will be there or there abouts, given a fare win, but Button won't win unless it's wet. Hamilton is always worth watching and could mix it up with the Redbulls and Alonso. He went well in Spain which is a similar fast dusty track to Turkey. The F-duck will keep them in the hunt but Ferrari and now Redbull will have F-ducts too though not as developed and attuned as the McLaren version.
Rosberg and Mickey will be back scrapping about behind the rest, probably ahead of Kubica if they have no problems.
So yeah, the betting money is on a Redbull 1-2. I can't think of a reason to doubt that personally.