As a technologist, I hope most people can see the real value being added by the Surface over the iPad, and I think the corporate / enterprise angle is being lost entirely in this analysis.
On the other hand, you're absolutely right about Microsoft taking a loss to gain market share. Xbox was first, and is now the most popular gaming console in the world. Then is Bing, which despite not yet turning profitable for Microsoft did prevent Google from attaining a monopoly and has made Microsoft the only other company with a legitimate index of the internet and reasonable market share in search. I can definitely see Microsoft taking some hardware losses on the Surface to plant the seeds for the Windows 8 ecosystem.