Microsoft's own batch of "Windows 8 Hardware Certification Requirements" documents, released last month, reveal that the company is providing minimum hardware requirements for x86, x64 and ARM-based tablets running the upcoming Windows 8 OS. Devices will need at least 10 GB of free space, a 1366 x 768 screen resolution, Bluetooth 4.0 + LTE, a 720p camera and more.
The requirements are part of a 293-page "Windows Hardware Certification Requirements" document for client and server systems, covering aspects ranging from pen- and touch-based digitizers to WiFi Direct to power management. Starting on page 72, Microsoft begins to set the foundation for tablets, defining bezel width, boot latency, required hardware buttons and required components.
According to the document, a Windows 8 tablet must feature a power button, a rotation lock, a Windows key button measuring at least 10.5-mm in diameter, volume up and volume down buttons. "The default orientation is in landscape mode and the Windows Key button must be on the front of the device facing the end user in the center along the bottom bezel," Microsoft says. "If the system is a convertible, the buttons must be accessible in all configurations. For convertible systems, it is acceptable to have the button off center along the bottom bezel when the convertible is in its tablet mode. "
As for other specs, the tablet must support a minimum of 5 touch-based inputs. It must also feature WLAN, at least one USB 2.0 controller and exposed port, a gyroscope, a three-axis accelerometer, and a magnetometer. The bezel itself must not exceed 26-mm "to allow for users with smaller hands to access the edges while holding the device with two hands." However tablet convertibles with a hinge can have a bezel measuring more than the 26-mm limit -- up to 45-mm along the bottom edge closest to the hinge.
For more information, take a look at Microsoft's 2.13 MB PDF -- it's the first download labeled as "Windows 8 System Requirements" (windows8-hardware-cert-requirements-system.pdf) listed here.