This NYT piece explores what Osama bin Laden might be trying to accomplish with the apparent moderation of his language in his audio pronouncements.

Some excerpts:

To change this, Mr. bin Laden is testing what he apparently believes are more mainstream themes, while trying to dislodge the entrenched American view of him as a terrorist hell-bent on destroying America and all it stands for. In the pre-election address, Mr. bin Laden said Mr. Bush was wrong to "claim that we hate freedom." He added: "If so, then let him explain to us why we don't strike, for example, Sweden."

That remark surprised some counterterrorism officials and terrorist experts, who said the Al Qaeda leader rarely injects sarcasm into his public pronouncements. They took it as a signal that he was trying to broaden his appeal, particularly to moderate Muslims and possibly even some Americans.

What they cannot say is whether the less strident approach means that he has changed his goals and is less of a danger or that he is just laying the groundwork to justify a new attack against the United States. But they are listening closely and debating an important question: Is Mr. bin Laden committed to destroying America, or has he become more pragmatic, trying to begin a rational foreign policy debate about its presence in the Middle East and even appealing to Americans' pocketbooks? ...

Does Mr. bin Laden's more moderate style mean there is less risk of a terrorist strike on American soil? Intelligence analysts are unsure. More than one analyst discerned an ominous warning embedded in his milder pre-election address.

"In Islamic jurisprudence, the warning is important," Mr. Bergen said. "And if we don't respond, it's our problem and our fault. He's putting the ball back in our court. Maybe this is all rhetorical and they don't have the ability to launch another big attack. But he intended to tell us that if we choose to completely ignore him, which is a very viable option for us, then we are going to get hit again."