Some great advice and travel tips from one of the absolute best in the business:
http://www.travelchannel.com/shows/hotel-impossible/video/resolve-hotel-bed-bug-problem
are usually brought in by someone in their luggage or clothing. Not an indication of cleanliness.
^Exactly this. And ironically, the cleaner, better-rated, and more popular of a facility, the more likely you are to have bedbugs enter. More travelers coming through your doors = higher risk of unwanted luggage hitchhikers. So obviously WDW is a higher risk of having bedbugs than, say, Uncle Joe's Roadside Inn off exit 4056 in the middle of Nothingsville. Yet while any place that depends on guests as a source of revenue is at high risk of getting bedbugs...with the right professional procedures in action, any and every lodging facility, movie theater, hospital, or public aircraft can quickly evict these critters as quickly as they entered.
The bad news is, until we have a better educated public on the do's and don't's of bedbug-prevention travel habits (check thoroughly before cozying into your room, never just go in, throw down your luggage onto the beds/floors, and so on), these little pests will remain a nasty annoyance.
The good news is, they're just that, annoying pests. They aren't going to kill you or inflict some sort of illness. As a matter of fact, a gnat, housefly, or any form of currency in your wallet right now contains more germs & greater risk of getting you ill than you can ever receive from a bedbug. But because the name inflicts such gross impressions and fear (naturally, it's never pleasant to hear "bed" and "bug" in the same sentence, let alone word), these critters have somehow managed to become the more feared, apocalyptic media focus.