Dan Drezner thinks Obama's speech was nice, but mostly irrelevant:
There is no public clamor or enthusiasm for yet another military engagement, nor do I see any genuine policy appetite for such a move. Sanctions are already in place. Covert action might be taking place, but that policy option can never be publicly acknowledged. As the New York Times story notes, in calling for Assad to leave the United States is now moving towards the consensus in the region. When the rest of the policy quiver has been exhausted, sure, why not call for Assad to leave? As a general rule, all else equal, I see no reason why the U.S. government should not express its actual preferences rather than hide behind diplomatese. Or, as Douglas Adams would put it, this rhetorical move counts as "harmless."
Marc Lynch, who Drezner pegs as an opponent of the move, appears to agree. Daniel Serwer looks at what comes next:
For President Obama’s new rhetorical line to be effective, other countries–especially Turkey, Saudi Arabia and the Europeans–will need to play hard ball with the Syrian regime. Both the Turks and Saudis have sounded recently as if they are willing to do that, and the Europeans in their own complicated way seem to be moving in the same direction. Diplomacy is getting other people to do what you want them to do. As many in the blogosphere are noting, Washington’s direct influence on events in Syria is small.
Jonathan S. Tobin, predictably, blames Obama for not doing this sooner, seemingly believing that the Syrian military follows Obama's orders instead of Assad's.
The Dish 