Sorry to say, but in an enterprise environment it really makes no sense to go with the Mac. Windows desktops and laptops are commodity items, replaced in 3-year cycles and ordered by the pound. In most cases it's actually cheaper to buy new than upgrade or repair existing systems. PC hardware and Windows 7 is 'good enough' for 90% of the business users who just need to do word processing, spreadsheets and email.
Precisely machined and polished laptop cases may be sexy and have lots of enthusiast appeal, but to an IT budget analyst for a large or even a small enterprise they simply do not make economic sense. A plastic cased Dell Inspiron will do just fine, at about half the price.
Truth is, Windows 7 is a pretty good OS. Microsoft learned some hard and harsh lessons with Vista and did a good job of cleaning up its act. Our experience has been that application developers have been sloppy with the transition from XP to Windows 7, and in particular the move from 32 to 64-bit platforms. This has caused a lot of implementations of Windows 7 to look bad, when it's really the application's fault (hello AutoDesk, you reading this?!)
Where Apple currently shines, and shines far brighter than any of the competition, is in the mobile OS market. Microsoft continues to stumble pitifully, Android is making strides but still not there (yet), but iOS is remarkable in its functionality and integration. I currently use my iPad as a laptop substitute and I'm amazed at how truly useful it is. The others will catch up eventually. They have to - it's a growing market with huge profit potential and they can't afford to ignore it or stumble. But right now in my opinion Apple owns the market segment (and I don't really care how many Android devices were sold last week or last month, it is still a disjointed market).
But watch out for Google's next move. One thing they learned over the last few years is that there really is a benefit to controlling both the OS and the hardware. Seems Steve was right, though Google will never admit it publicly. Google knows it needs an iPhone and iPad killer and the only way they can get that is to control the hardware environment. Can anyone say Motorola?