Heading into Apple’s iPad and Mac event this Thursday, there’s no question that demand for their smaller brother — the iPhone — is surging. A record of 10 million iPhones sold in the opening weekend is reportedly on the cusp of being trumped by an additional 20 million pre-orders for China alone. According to the Wall Street Journal, iPhone 6 and iPhone 6 Plus demand has so outstripped supply that Apple postponed a brand new iPad’s…