It looks like Bob Costas won't be Larry King's substitute host forever. "By next year he will be too busy with his HBO shows and NBC's football coverage," Alex Ben Block says. But it sounds like Costas is okay with that.

"I don't think I fully took into account how much the landscape had changed on cable TV, and that some of the subject matter that's kind of a staple of cable news television isn't necessarily my cup of tea," Costas said.

He's referring, of course, to the story TVNewser broke last month about his refusal to host a show about Natalee Holloway.

"Once it did get out, I was surprised but gratified that so many people had such a favorable response to it," Costas says in TV Week. "And beyond the public response, I can't tell you how many broadcasters and producers, people involved in television, have called or written or when I encounter them said, 'Boy, we're so happy you did that. We're so happy there was some statement, in effect, that some of this stuff is headed in the wrong direction.'"

> Update: 3:07pm: "Maybe Bob Costas should have actually turned the television on to watch CNN before signing his contract to become a substitute host on CNN. Had he never heard of Nancy Grace?," an e-mailer wonders...