How Mr. bin Laden feels about Israel's actions in Gaza is not exactly a shocker, yet his open "invitation" to take part in "jihad to stop the aggression against Gaza" could spur angry jihadis to action.
But how popular is bin Laden in the Arab world now? How relevant is he?
The question was put to CNN national security analyst Peter Bergen in a Q and A posted on CNN's website, and he had this to say: "He's less relevant than he might have been a few years ago because a lot of Muslims have turned against Al Qaeda because of its tactics and suicide operations. But there are clearly people who still think he's important."
The Monitor noted that the trend was under way in late 2007, reporting on Al Qaeda's waning influence in the Arab world:
Across the Arab world, where Al Qaeda had sought to build influence and bases of operation on the back of widespread anger against the US over its war in Iraq and the broader war on terrorism, the movement is now showing signs that it is stalled, if not in retreat.
Experts say Al Qaeda's failures have largely come down to its brutal methods, which have turned off large numbers of Arabs. They say that Muslims from Iraq to Egypt may want their countries to adhere to strict Islamic law, but not at the price of suicide bombings.
Just last month, the Monitor reported that an ideological clash between Osama bin Laden's chief lieutenant, Ayman al-Zawahiri, and Imam al-Sharif, the jailed ex-leader of Egypt's Islamic Jihad, could weaken support for Al Qaeda.
Lest anyone become complacent about the resonance of bin Laden's messages to jihadis around the world, however, CNN's Mr. Berger points this out:
Sometimes he makes specific calls for attacks on particular places. For instance, he called for attacks on Spain, and there were attacks in Madrid in 2004. He called for a response to the Danish cartoons of the Prophet Mohammed, and there was an attack by Al Qaeda on the Danish Embassy in Pakistan last year. And I can give you several other examples.
With rockets now coming into Israel from Lebanon, those instances are probably worth remembering.