Nikon's D4 is currently the only belle at the XQD ball, and until now, Sony was its only memory suitor. However, Lexar's just arrived with a new line of cards to compete for the D4's affections. The Fremont-based company says it collaborated with Nikon to build the PCI Express-based memory, and that they'll hit the market sometime in the third quarter of 2012 -- with no mention of specs or prices so far. Unfortunately, that means we don't know how Lexar's offerings will stack up against Sony's
