George Stephanopoulos of Good Morning America praised Katie Couric's recent stint filling in for co-anchor Robin Roberts."It was a lot of fun to work with her. She had not lost a step in six years off. And you know, I just feel so blessed. Because I get to work with Katie Couric for a week, and then go back to my regular partner, the superb Robin Roberts. And it's a great privilege to be able to sit next to her every day," gushed the GMA host, ever dlplomatic.