Nintendo making motion-sensing DS card?

A recent Japanese trademark threw up some flags over at Siliconera, as Spencer managed to find an odd one. Apparently for a motion-sensing DS card, the title for the trademark reads as "DS Houi Sensor Card". Curious, to say the least.

Houi means direction, so it leads one to deduce that it's a card that senses direction or, more likely, motion. What's most interesting about this is Nintendo apparently means to include this technology directly into a DS card. It'd be like being able to play WarioWare Twisted! on the Nintendo DSi. Yeah, that would be awesome.