There's a lot of if's with KC. If you're counting on Steve Breaston, who's been terrible on the rare occasion he's actually been active to be your #2, you're in deep trouble.
I'd be fairly surprised if KC was .500 next season, but their schedule will certainly be softer. KC fans don't like it, but when good teams play bad teams, they often play down to their competition. Indy, Pittsburgh, Baltimore, Denver all basically sleep walked through their games with KC.
Look at Jacksonville. 4 of their last 6 games, they were within a TD of winning (or won). I don't think anyone actually thinks the Jaguars are a player or two away from being right up there with New England and Houston.
Worst thing Chiefs management could do would be to think they could put a band aid on their roster and fix all of their problems.