The Apple iPhone Duo is available for pre-order starting today – or rather we should say that it was available. The very limited supply became painfully apparent when mere hours after launching, Apple’s online store was already showing a shipping date of January 22.The original plan was for the iPhone Duo to start shipping on October 23 after a week of pre-orders. And some people will surely get theirs on that date, but most Duo buyers are in for a wait.We checked the online store in multiple countries: the US, Canada, the UK, Germany, France, India, Australia, New Zealand and...