Is Osama bin Laden still relevant? Or rather, is the threat more from a reconstituted, centralized Al Qaeda, or from more local groups radicalized by preachers or outside forces (see recent arguments between Marc Sageman and Bruce Hoffman). Also interesting to consider is how centralized Al Qaeda was before September 11, looking at the scope of its attacks both prior to and after September 11.
Which is more dangerous, a decentralized Al Qaeda operating as a symbol, or a centralized Al Qaeda still ordering attacks from a mountain redoubt?