It's time for a reality-TV reality check. Even top executives and producers admit that the genre has become tired - an overload of singing battles, food challenges, screaming housewives and dating competitions. "We've been in a huge reality drought," says Greg Goldman, the new president of Studio Lambert USA, which produces Undercover Boss.The broadcast networks continue to coast on the enduring success of veteran franchises like Survivor, but they're not minting many new hits. In cable, the success of docuseries like the Real Housewives franchise and Love & Hip Hop has led to a glut of such shows.But a shake-up may finally be on the way. CBS recently named a new head of reality TV, Chris Castallo, while Fox is looking to fill the top job in its alternative department (which infamous reality kingpin Mike Darnell vacated at the end of July). There's also a new head of unscripted TV at AMC, while TruTV and A&E, both big reality networks, have new bosses.