How about an Arduino style super computer the size of a credit card

64 1gig(dual core) processors on something the size of a credit card, for $99...

Not quite. The Epiphany processor contains 64 single cores. The Parallella board contains an Epiphany processor, and a Zync-7000 ARM9 dual-core soc to interface the Epiphany to the rest of the hardware. Still pretty interesting though.