Nerval's Lobster writes "Apple's long-rumored "iWatch" could earn the company $6 billion a year, if an analyst quoted by Bloomberg proves correct. Citigroup analyst Oliver Chen estimated the global watch industry's annual revenue at $60 billion a year, with gross margins of roughly 60 percent. "This can be a $6 billion opportunity for Apple, with plenty of opportunity for upside if they create something totally new like they did with the iPod," he told the newswire, "something consumers didn't even know they needed." Meanwhile, The Verge reports that Apple has " chosen to rework the full iOS to run on the watch instead of building up the iPod nano's proprietary touch operating system," which has led to battery issues: while Apple would like the device to last "at least 4-5 days" between charges, the current prototypes give somewhat less. While an "Apple TV" long dominated the rumor mill as Apple's next big product, the frequency and detail of "iWatch" rumors over the past few weeks suggests that a timepiece could be the company's next big project."