You've waited a long while for this day to come, but here it finally is. Apple is today rolling out iOS 4.2.1 to iPads and qualifying iPhones (3G, 3GS and 4) and iPod touches (second, third and fourth generation) across the globe, delivering the long-awaited multitasking and app folder enhancements to a tablet that was already supposed to be magical and revolutionary. To see whether this new update -- replete with Game Center, AirPlay and AirPrint additions -- really he