Since AppleTV had renting movies before, I don't see why they would exclude them from renting TV shows now. They'd only miss out on renting-business. Of course they won't bring netflix etc., but renting TV shows... I don't think that even requires a software update... But *if* so, you'd simply rent them on your Mac or PC and then sync.
Mac user since 1987. Running Mac OS X 10.8 Mountain Lion on a MacBook Air 11" & an iMac 27" and whatever's newest for my iPhone 4s, iPad 3 and AppleTV 2.
Apple Certified System Administrator 10.6, Apple Sales Professional 2008-2011, Apple Certified Mac Technician.