A "mid 2014" Mac mini is now listed on an Apple support document for Boot Camp. The page makes no mention of other details about the computer, other than it only supporting 64-bit Windows 7 and 8 versions of the Boot Camp utility, which allows Macs to run Windows on a separate partition. The Mac mini has been one of Apple's most neglected products, having last been updated in late 2012. Even the Mac Pro was refreshed in December 2013.
If the listing is accurate, it implies that a new Mini may be imminent, shipping within the next month. Apple today updated the MacBook Pro lineup with faster processors and more default RAM. New Mini models could get similar boosts.