I copied the cover and uploaded it so it would display here. Here's a link to the cover on the NYer site along with a subscription pitch. This is already last week's issue but I am pretty sure it can be ordered. BTW It's not a bad magazine to subscribe to if you are an effete pretentious would-be elitist.

http://archives.newyorker.com/?i=2010-08-02

Just checked The Cartoon Bank, where you can order prints of some NYer covers and cartoons (or even buy the original art for $2K and up). They have quite a selection of covers by this artist, Jean-Jacques Sempe, and it would not surprise me if this one becomes available. Prints start at $125 matted.