I've talked to two friends who ran it and both came in 30+ minutes over their goal time. One in 4:30, the other in 4:50. Another dropped out at mile 14.
It sounded brutal and if the crowds didn't have hoses and ice, would probably have been worse. When you train in the spring conditions we've had so far there isn't much acclimation to 90+ degree temps.
I think the race director was wise to close the course. Certainly most of those runners who witnessed so many beaten by the heat would be somewhat understanding of the decision.
You can train and do everything right but Mother Nature is the unknown factor at marathon time.