I thought it was generally agreed upon that 2 marathons per year was the max for most elite runners if they wish to perform well at both. It did not make any sense to me for Kenny to run Dubai, but at the same time I think we will see great things from him in the future. Not 26:17 great, but great things.
I think even Geb DNFed half a dozen or more times before he ran his marathon WR. Today's performance form Kenny B means nothing.