Okay here is my prediction based on this rumour
Name
Nintendo Go
Media
Cartridges
Power
×1.5x better than Wii U in docked mode
System Features
Handheld Mode
System is basically a small 7" tablet with a 540p capacitive touchscreen. Can be used as a iPad. Can add attachments on each side of the unit for traditional controls. System also has camera and gyro for AR features
Console Mode
There is a docking station that has a HDMI passthrough and charges. Once the system is on this docking station system overclocks for higher resolution graphics it allows this to happen as system does not have to worry about battery life in this mode. The 2 control attachments can be attached together to form a regular controller. The docking station also has wireless video streaming for instances you want to use the 2 screen features for some games like the Wii U.
That's a good guess for the name. From a marketing perspective, "Play/Fun on the Go" writes itself.