He says no.
From The Hollywood Reporter:
THR: With all the talk that Katie Couric might leave the CBS Evening News, your name is rumored on a short list of people CBS might be interested in. Is that something you’d like to do?
Chris Wallace: No. First of all, I don’t think they’re going to ask and second of all, I’m very happy at Fox News Channel.
As much as I grew up in CBS and as much as I associate that anchor chair with Walter Cronkite and the history of broadcasting, I have never been so happy as I have working the last four-plus years at Fox. I suspect I’ve had a much better last couple of years than Katie Couric.