This is the DEK and it may be the first video game peripheral designed to work with the latest, wildly unpopular Tony Hawk skateboarding and snowboarding games that require dedicated skateboard controllers to play.
The DEK is, quite simply, a mat on which players use their Tony Hawk Ride and Tony Hawk Shred skateboard controllers. It has more friction than, say, carpet. And maybe it will help protect your hardwood floors? Its makers say the mat “boosts stability and connectivity with Wii, Xbox and PlayStation programs”. By raising the sensors above the floor surface, it “improves synchronisation with the console”.
A DEK mat was sent to Kotaku HQ recently and, yes, it would appear to give players something more stable on which to fake-skateboard. Just don't expect vast improvements in actual game quality.
Pro snowboarder Pat Milbery says DEK was "created to put millions [sic]of consumer complaints to rest", which might actually be true if he's referring to the version made specifically for the Wii Balance Board.