I don't think the capture of Osama is important as far as combatting terrorism goes; I think that anyone who thinks its a major blow needs to clue up. Its more of a domestic victory; both a morale booster and the tying of a loose end. Whilst the concept of a morale booster might seem silly, and to some extent I agree, a feelgood factor can easily find its way into the economy, which in times like these is important. Short or long term, people will take any gain they can get right now.
