The irony is that Bekele himself contributed to the rise of the marathon in the last 5 years.
First, Geb was so dominant, then came Bekele and a ton of people couldn't make it on the track circuit because they could never beat those two over 5k or 10k.
If you were a teenager in 2004 and looked at those events you were probably thinking you had to move down to 1500 (and face El G) or jump straight into the marathon.
Fast forward to 2005 and Sammy Wanjiru is a 19 year old and he runs 26:41 (26:41 at 19!!!!) and he got beat by 20 seconds in that race!! And by a guy who was only 23.
Well Wanjiru wasn't going to settle for second place for his whole life so he jumped to the marathon and became a legend on the roads.
And a ton of young east Africans followed his lead so that there were 6-8 people who have been conceivably capable of breaking the marathon WR in the last 3 or so years.
Now Bekele has to step into a much more competitive marathon scene than Geb did. The days of aging stars just moving up to the marathon are over because the marathon is a young man's race now.