I missed this one before, when it was announced at Electronica: the Uno SPE Shield, created by Arduino and Microchip working together. It turns out, though, that it wasn't available back then. And it ...

The new Shield has been designed to provide a common shield for Raspberry Pi and Arduino Uno development boards with Motor Drivers, RTC, Temp, IR Sensors, IMU & 2 Cell 7.4 V Li-ion battery charger ...