Howard works for Infinity, a division of CBS under Mel Karmazin. He will stay there as long as he wants. He's got two years more on his contract, and he may want to leave when it's over. He's doing a lot of television production, and could have some movie deals if he weren't tied to his radio show.
He is a cash cow that that company, and they love him. He's been in business for over 20 years, so I'd say he has some staying power, through good times and bad.