I am not that big on speculating who will win such prized events like Kona, as there are so many independent variables, but here goes.

Assuming no bike or health issues then Chris McCormack to win. Also of course Craig Alexander to be at the front.
Enoeko Llanos challenged Chris McCormack all the way in 'Ironman Germany' in the fastest times this year, so it wouldn't be a surprise to see these two battling it out in the run.
First of all lets look at last years results. There are a few names missing from this list that will be looking for redemption. Several of these athletes were unwell last year even though they did start and include the previous two times champion Normann Stadler and of course Faris Al Sultan. Faris really showed his dominance in several races earlier in the year but Normann has been lying very low and had to pull out of this years Ironman Germany also due to illness.
Cameron Brown has a great history in this event and looks to be having a great build up this year.
Francois Chabaud has been racing fast and should be in the mix for a top result also.
Other athletes with recent top form who could easilly break into the top 10 this year are Andy Potts(current 70.3 World Champion) and Bryan Rhodes. If like Chris McCormack says, " the heat is tough on the bigger athletes" then these 2 could struggle along with several others if it is hot.
Frederick van Lierde and Luke McKenzie are two other names I will put in the hat to do well. And I wouldn't be surprised to see Keiren Doe mixing it out the front with the lead cyclists.
It would be great to see the strongest cyclists giving it their all from early in the bike leg, rather than all the strategic worrying/jockeying for position that has been going on in recent years at Kona. I do however think that the race will be won by the best all round athlete and not the fastest bike split of the day however.
It would have been great to go along and photograph this event myself this year as it should end up being very exciting; maybe even approaching the great 'iron wars' of the late 80's.
Some of the athletes I haven't mentioned haven't been racing as often so maybe some of them are focusing 'big time' on Kona. It is a bit of a guessing game unless I heard from them directly or their training partners/coaches.
Scott Molina(45-49) is also entered and it is inspirational and great to watch how athletic the previous winners of this event remain as they get older.
Thomas Hellriegel is another name I associate from the past with strong performances at Kona.
My tip would be to do the 70.3 Hawaii Ironman earlier in the year and I certainly looked at this when compiling the above. It is at a different time of year so the weather is likely diiferent but if it covers some of the same course it can only be of use in the build-up the same year. Basically training on the course and acclimatising well to an area by spending more time there will give some advantage.