Middle East Respiratory Syndrome (MERS) was first discovered in 2012, and has killed roughly 200 people since its discovery. Two cases have been found in the U.S. Now, according to a May 26, 2014 article on BBC, scientists are attempting to unravel the mysteries of the disease. They're going to start testing dogs, cats, rats, and other animals that are normally in close contact with people, to see if they're carrying the disease.
MERS is a coronavirus, which is in the same family as the viruses that cause colds and other minor to moderate respiratory illnesses, according to the CDC. Coronaviruses aren't unique to humans; in cats, a coronavirus infection can lead to feline infectious peritonitis. The current assumption for cats is that the specific coronavirus mutates, and causes FIP, but it's not transferrable to humans. Cats usually don't show any symptoms of infection until after FIP develops.
Scientists are looking into MERS in domestic animals, like cats, because they believe that particular coronavirus transferred from animals to people at some point recently. Researchers have found antibodies for that coronavirus in camels, indicating that they are a possible vector for the disease because the MERS virus currently found in people is indistinguishable from the one found in camels.
There's a problem with assuming that it's only passed from camels to people, though. The CDC says that the coronavirus is very common in camels in several African countries, showing that the virus is far more widespread than originally thought. However, the BBC article mentions that there are people who've died from MERS who had no known association with camels, or people who'd been in contact with camels, indicating more than one vector.
The World Health Organization is most concerned with the human cases of MERS; the research into animal carriers is primarily to determine where all the vectors are. There are some diseases you can catch from your cat, such as cat scratch fever, roundworms, hookworms, and toxoplasmosis are among those diseases. The Cornell College of Veterinary Medicine lists more here. However, it's not especially likely at this time that you'll be able to catch MERS from your pet cats, especially if they're indoor-only cats.