That price would effectively mean that Microsoft is going to subsidize the tablet as it is impossible to produce+sell it with a profit at that price level. For reference, Ubergizmo estimates that ASUS makes a $3 to $4 profit on each Nexus 7 tablet, which uses a similar Tegra 3 chip, but has significantly cheaper battery, a much smaller screen and overall material.
This is a business model that Microsoft knows well: its Xbox 360 console initially lost money on the hardware only to make it profitable on the game sales. However, this is a very different business, and chances are that the lifespan of the Surface for Windows RT tablet (18 months vs. 7 years for the 360) won’t allow Microsoft to make the money back. If this $199 is true, I would see it more like an move by Microsoft to expose customers to Windows 8 RT – but without a real chance to make their money back.
That seems a bit too good to be true, but we’ll have to wait and see. Microsoft has a lot of cash, and how they use it can be a mystery. Surface RT for $199? I’ll take two!