Although our gut reaction to seeing the words "new" and "memory card specification" in the same sentence is a hearty "WTF mate?!", the SxS format seems to be different, and perhaps justified. Sony and SanDisk are teaming up to produce the SxS cards to be compatible with ExpressCard slots and be used in pro camcorders—like the ones we're seeing at NAB this week—and are useful for people who really need quick access and transfer speeds.
How fast? How about 800 Mbps? Plus it's going to be nice and thin at only 5mm, so it will fit into the sleeker pro cams that are all the rage these days. The first camcorder from Sony to support this format will be the XDCAM EX series, which are available later this year.