“Ted and I talked about me filling in for him at Wesleyan University earlier this week,” Mr. Obama said in a statement. “Considering what he’s done for me and for our country, there’s nothing I wouldn’t do for him. So I’m looking forward to standing in his place on Sunday even though I know I won’t be able to fill his shoes.”
EDIT: President Roth confirms via email:
It gives me great pleasure to announce that on Sunday, May 25, 2008, United States Senator Barack Obama will deliver the Commencement Address at the 176th Commencement Ceremony at Wesleyan University in Middletown, Connecticut.

Senator Obama is honored to speak on behalf of United States Senator Edward M. Kennedy, who was previously scheduled to deliver the address.

. . . (quotation above follows)
[Marianna, 4:29]