Natural user interface controls such as touch are expected to be part of Windows 7. I asked Brad Carpenter, general manager of Surface software, whether developers building applications that take advantage of NUI in Surface would be able to transfer those skills to Windows 7.

"Absolutely. ... Between the work in my group here at Surface and the Windows team and the WPF [Windows Presentation Foundation] team, we are creating a road map that will converge with WPF 4, that will be out some time after Windows 7, that will enable you to have a consistent interface to develop to. An application that you design to run on Windows 7 for touch will be able to also run on Surface, with a minimal amount of work to do that."

Surface, of course, has some unique attributes, such as object recognition, that won't be part of Windows 7. These will require additional controls be added back to the Surface apps, Carpenter said.

Microsoft will have 16 Surface units in the Los Angeles Convention Center for developers to play with and plans to release a software development kit for the new computing platform, but will initially limit distribution of the SDK to 1,200 downloads. The company discussed earlier plans for a Surface SDK in August.

"We believe this is a good opportunity for us at this stage of our business to start to enable the development community to get onto the natural user interface wave," Carpenter said. "We see the NUI [as in natural user interface, pronounced newie, rhymes with gooey, or GUI] as a major inflection point in computing today and we believe that Surface is at the forefront of that."

Beginning Monday, developers interested in building applications for Surface will be able to purchase a unit and a five-seat development license for $13,500. Carpenter said developers have already snapped up many units. How many? "In the low hundreds," he said.

Microsoft thinks there's huge momentum behind natural user interface, which is a key feature of many new cellphones, led by the Apple iPhone. "We believe that this will be a multi-billion dollar ecosystem by 2013," Carpenter said.

Considering the relatively slow pace of initial Surface deployments -- there were only about 63 commercially deployed when I last counted in August, more than a year after the product debuted -- I wondered how Microsoft expects to get there from here. Is a consumer version of the device, as alluded to in a Microsoft consumer survey recently, still in the works?

Carpenter said the company is initially targeting commercial customers in the retail, hospitality, entertainment, health care, banking and automotive industries.

"But there are obviously several other places to go and ultimately we believe that there is an opportunity in the consumer space, and it is something that we're researching," he said.

The company said last year that its goal is to have something for that market in three to five years. "I guess now we'd be on a two- to four-year time frame," Carpenter said.

Check back next week when I'll be in Los Angeles covering PDC.