Windows Phone 7 restricted to just three chassis types?

Manufacturers looking to release Windows Phone 7 Series handsets will be restricted to a choice of just three hardware designs.

That's the claim from Michael Kordahi and Andrew Coastes, two employees of Microsoft Australia, who shared their views on the new platform in their Frankly Speaking weekly podcast.

While the pair freely admitted that their comments were a mix of facts and predictions, they did specify that Windows Phone 7 Series hardware would be restricted to three hardware variants.

Microsoft's new mobile operating system was broadly praised when it was unveiled at Mobile World Congress in Barcelona earlier this month, but at the time it wasn't clear the hardware specifics Microsoft would require from forthcoming devices looking to use the platform.

According to Kordahi and Coastes: "We're talking about three form factors at this stage." The OS will make its debut on devices with the same form factor as the demo handset showing off the OS in Barcelona a touch-only chassis powered by the near-ubiquitous 1GHz Snapdragon processor and a dedicated graphics chip.

The second chassis type will be a slider form factor featuring a combination of touch screen and QWERTY keyboard, much like the Palm Treo, say the Microsoft Australia pair. Details on the third chassis have yet to emerge, they say, but predicted that it will be based on a basic candybar shape.

While the three-chassis model places far greater restrictions on device manufacturers than was the case with Windows Mobile 6.x, it's a development Microsoft itself has been saying for some time was inevitable.

"In the future, we are looking to deepen our development work with a handful of key OEMs at the hardware design phase," Microsoft business marketing manager James McCarthy said in September 2009. "With much more carefully defined hardware specifications to match software requirements, which in turn will deliver even more powerful mobile experiences for our customers.

"This has led to this chassis concept that is familiar to the work Microsoft does with hardware partners in the PC industry to create high quality products."

Prior to Mobile World Congress, Microsoft was strongly rumoured to be working on a hardware device of its own, dubbed the "Zune Phone". It remains to be seen if such a device is still in fact on the horizon, or if the rumour simply grew from Microsoft's involvement in conceiving these hardware chassis types referred to by Kordahi and Coastes.