Apple is on the verge of updating the iMac lineup, several sources tell Fox News. The news agency doesn't elaborate on the claims, but does note that Amazon is out of 27-inch iMacs, while Apple is low on stock of them; 21-inch iMacs are still said to be widely available. When Apple might announce the new computers is unknown, but Fox's Clayton Morris says that he isn't holding his breath for it to happen at a rumored October iPad mini event. Apple sometimes updates its desktop computers outside of press events.