mold, im not sure that i would try to re-use these seeds though at the risk of having this mold progress into something that could spread down the road to other plants, ruining your entire grow for 2013.
Try to save a few molded seeds VS mold progressing and effecting your entire grow.
My opinion, its mold, trash them and keep a close eye on the other seeds from this same lot.
also, you should treat your seeds prior to germing if you dont already with diluted bleach/water or hydro perox mix.
dustin's right, once mold is started, getting rid of it is practically impossible.