This shirt MAY have been available somewhere on the internet before Winter 2007.
The theme of black and gray fits Shadow the Hedgehog well for this long double-sleeve shirt. Walking Shadow (in color) divides between two different expression portraits in black & white. The Sonic X logo is present, but subtle.
This shirt isn't spectacularly new or different, but it should go with just about anything and has a subtle cool. Be sure to check your local Sears for sales on it too!