It's not your imagination — there really are that many reality shows about swamps, weddings, Louisiana, and cake. And here's visual proof: The following Venn diagram maps the overlapping relationships between reality shows. Included on this chart are only shows that aired in 2011, 2012, or are scheduled for or are in development for this season (and in a few rare instances, there are notes on reality-TV niches not yet filled). The reality-TV universe is even more repetitive and connected than you could have imagined.
Two small caveats: Wedding Cake Wars ended in 2009 but was too perfect a fit not to include, and Bear Swamp Recovery is not set in a swamp, it's merely named for one.