I don't know if it's happening at MCO specifically, but yes, airports have been warning (and actually emailing passengers) us all of 3+ hour waits. O'Hare is getting the most press about it (a video was posted of the line), but a friend in Austin had a similar experience two weeks ago and here in San Jose the waits are also reaching 3 hours.
It's a problem at ALL airports and it's because TSA is understaffed. They are warning people that it will be occurring all year and especially at holiday season. "Hold on to your butts!"