The beta version of the new operating system has been up on the interwebs recently and the reviews are very good.The focus is on efficiency and the hardware needs are reduced vis a vis Vista.Microsoft Office is far ahead of any competition such as Open Office and cloud computing at present is simply not ready to take up business needs.Microsoft derives most of its revenues from these cash cows.
Apple inspite of everything the fan boys have to say is overpriced and in this economy,Microsoft has the edge.
Linux will see increased usage but given a good stable Windows,many people will prefer to stick with it.It is still not as user friendly as Windows and the quality of applications in certain areas are nowhere close to that available for Windows.
Financials
Cash rich enterprise
Disclosure:I use Dreamlinux but then I am a geek.