So much for not keeping pace, huh? We heard back in June of last year that Microsoft had blown through 150 million Windows 7 licenses, and just a few months later, it had surpassed 240 million. At this year's Worldwide Partner Conference, head honcho Steve Ballmer took great pleasure in announcing that said figure has now swollen to beyond 400 million in under two years. Not surprisingly, that makes Win7 the fastest-selling operating system in history, and Tami Reller -- corporate vice president and chief fina