I'm sure the other thing Microsoft are considering is the increase in the up take of the "BYOD" strategy companies are taking (BYOD = Bring Your Own Device). What this does is give company workers the ability to buy their own laptop / desktop / tablet (with a subsidy paid by the company) and the company then rollout their standard applications to this. This can be done via a variety of methods (some of which allow Windows programs to run on Linux / Mac operating systems) - this means some companies limit choice to certain devices, whilst others allow their users to get anything they want.
The advantage for the user is, they get their own home device with a large part of it paid by the company meaning they can get something much more expensive than they'd usually get. The advantage to the company is, they don't have hundreds / thousands / tens of thousands of laptops on their books, gradually ageing, losing value, requiring replacement or expensive warranty extensions etc. etc. Take away all that management and save yourself a lot of money. Generally, if done right, you can also ensure the security of company data much more easily and make activities such as patching, new application rollouts etc. etc. much easier (again saving money over the traditional approach).
How does this all affect Microsoft? Well, you only have to watch TV and you see virtually every one nowadays uses a Macbook. Maybe a few people have a Sony. But they're nearly all MacBooks. And, as we know, people love their iPhone and iPads. I'm pretty sure many people don't buy MacBooks because of the price. Now imagine suddenly your company is giving you £500 (or possibly more) to go towards your own laptop. That Macbook suddenly becomes a lot more of an attractive option.
Microsoft are desperately trying to up their image. Their advertising is now much more "cool" (sorry, not sure how else to describe this!). Not even willing to rely on 3rd parties to design PCs any more, they've taken the unprecedented step of developing their own hardware (the Surface and soon to arrive Surface Pro) - both very desirable bits of kit. Windows 8 is another step in the process - it's designed to attract the consumer because, in tomorrow's corporate world, it could well be the consumers who decide what work device they use.