What came first, the SDXC card reader or the the SDXC card? Also, could that be the worst riddle of all time? Maybe! Partly because it doesn't really work, and partly because Elecom has already answered it.
Elecom's MR-A001BK will be, to my knowledge, the first SDXC reader on the market, hitting (Japanese) streets later this month, about the same the first 64GB+ SDXC cards start shipping from reputable manufacturers. It only supports SDXC cards up to 64GB, which is just a fraction of the spec's limit, but which'll cover most of the first generation of SDXC cards, or at least the ones you can afford. Price is said to be 1890 yen at launch, which converts to about $24.