Jim Lanzone of Ask Jeeves posted a Thanks, Jeeves blog entry at the Ask Blog. He explains all the reasons why it is time for Jeeves to retire, in that blog post, so it is worth a read. There is also a special Jeeves retirement site at www.jeevesretirement.com/desk.
The Ask.com homepage currently is sporting a link to it as such;
Chris Sherman has the official Search Engine Watch article on Jeeves Retires.
Forum discussion covered here. Goodbye Jeeves.