Some people are classy, and retire when they are at the top of their game (Sir Terry Wogan as an example - when he left, he was hosting the #1 rated UK breakfast show). Then there's Larry King. To me, he's there for the paycheck in some respects... he may well love his work and is doing it because he still loves it - but he is to me less and less effective in his role these days.
I think Larry King should retire from weekday duties to a weekend show instead. He wouldn't be fired, his workload would be lessened, and King fans can still get to see him, just not in the week. He can then concentrate on interesting interviews and not have to worry too much about "breaking news".