I agree Wanjiru seems to be a confident guy and if his tactics in Amsterdam are anything to go by, he is the favorite. That said, Tamirat show in Dubai was also superb and if he shows up in similar shape then we got a show to behold in London. And don't forget the defending champion, diminutive Eritrean Ghirmay. Since his win in 2015 he has placed 4th in the Virgin London marathon, won New York marathon and placed 4th in the Olympics last year and all against the best fields. Championship races are his strength and he could come through for a back to back title. Kirui on the other hand is a strong athlete and certainly has a great future but he might not have what it takes to win a championship race since he tends to be slow when it comes to changing gears. That is why even with a sub 27 minutes PR back in 2012, he could not win the world juniors, only running 28:30 to finish 3rd.
The third Kenyan, Paul Lonyangata is a puzzle. The fashion in which he won Paris marathon indicates someone who has matured and if he goes on to win, it won't be a surprise. He certainly demonstrated he could mix up with anyone including the likes of Bekele and Kipchoge.