Let's assume that he is still in his early 20s and is starting from scratch. He will have no lifetime aerobic base to fall back on, as he has lived a sedentary lifestyle up to this point. He is average weight for his height. All he has is his genetics. Given 2 years to try, would this version of Bekele break 15:30 for the 5k off of 5 miles per week? If more than 2/3 of you say "yes" I am going to completely retire from anything resembling competitive running and just jog to stay fit or something.
Oh, and BTW, no cross-training is allowed. The 5 miles a week is the only physical activity he gets.