In light of my recent post on "stocks for the long run" Zvi Bodie argues why the idea of "stocks for the long run" is flawed. Transcript and audio is here
His basic idea, which is not new, he's been harping on it for a long time, is that stocks will on average beat bonds, but only on average. This means that the average investor will do OK investing in stocks for their retirement. But some investors will do a lot better than average and some will be do terribly (and end up eating dog food in their old age, as Zvi elegantly states). As an individual investor has only one shot at getting it right, being right on average is not too helpful.
Definitely worth listening to.
Incidentally, this is finance fallacy number 2, I'll have to look up what #1 is.