Speaking to financial analysts, Microsoft VP Terry Myerson declined to directly answer a question about whether current Windows Phone 7 owners would be offered an upgrade to Apollo (Microsoft's code name for WP8) but implied that such a move would create significant logistical issues between the company and its hardware and carrier partners.

"Even if we were to say all phones can be updated, then you get into the--you know, our business model implies layers of supply chain to get it out to them, and there are certain incentives to get it out to them that have to be talked through, so there's nothing to announce there," said Myerson.