This takes the dumbing down of track into the next stratosphere. They are two completely different athletes. Is there something wrong with appreciating them individually?
This would make that silly Donovan Bailey/Michael Johnson 150m look really legitimate and important. Bolt and Bekele are both really good-natured toward each other and have no grudge about who is "faster" or anything. So it would basically be like two buddies going to play golf, and one of them is a monster off the tee, while the other is a wizard on the greens. Who cares?
If the two of them really want to, fine. But if anyone thinks this is an awesome idea, it's not.