RE: The heat, I'll say again expect a race like Edmonton 2001 Worlds: A shitload of DNFs and a winning time of 2:12 or so. It was 80 at the start of that race and dewpoint was in the low 60's. Interesting that an Ethiopian and Kenyan took a close 1, 2, followed by the Italian Baldini.
I agree. Also, there is a big incentive for the internationally competitive runners who can garner appearance fees to give up if they think they are out of the medal race. They don't want to hurt themselves and miss out on fall marathon money. Thus, a runner like Sell who will finish or be taken off on a stretcher may be a good call for a dark horse.
And the runners in Beijing will wish that the dew point was in the low 60s.