"The two first met in 2004. Rudisha, a Masai, was 13..."
But earlier the article had spoken of this year's "goal for Rudisha, 24..."
In other words, the man has aged eleven years between 2004 and 2013, a nine-year span. That means eleven of his seconds are only nine of ours (the rest of the world's).
So a sub-1:41 for him would be like a regular person running a 2:03 or so--a good time, but it would lose a lot of high school races. This, to me, makes his world record much less impressive.
On the other hand, his ability to live on a different time scale than the rest of humanity is impressive as hell!