Microsoft could be preparing as many as six new form factors for future Windows Phone devices. General Manager of the Windows Phone design studio Albert Shum shared a slide with TechRadar that illustrates an ecosystem with multiple form factor devices based on Microsoft’s mobile OS.

The slide is of particular interest after an internal video leaked last week that revealed a ton of new details about Microsoft’s next generation handsets. In addition to the full microSD card support, NFC functionality and multi-core processors, we now know that four different screen resolutions will be utilized across the range of products.

If the icons in the slide are drawn to scale and the largest one is excluded as a tablet device, things certainly become pretty interesting for Microsoft and Nokia. The largest non-tablet device appears to have no physical keyboard or buttons and could rival the 5.3-inch Samsung Galaxy Note. A slightly smaller device is also shown with what could be physical buttons across the bottom in portrait mode much like many Android devices that shipped last year.

An even smaller device with a physical keyboard could cater to the business crowd à la RIM’s BlackBerry. An even smaller handset would likely be marketed as an entry-level device for teens or emerging markets, but the most interesting illustration in the slide is a tiny square product that seemingly rival’s fitness-related gadgets like the Motoactv or even Apple's iPod nano.

The latter certainly seems plausible as Microsoft publically killed off their Zune HD media player late last year.

Image courtesy TechRadar.