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 H-series or S-series cards already on the market. That said, while you wait for more details about Lexar's new cards, feel free to check out the lovely data the D4 will be putting on 'em when they arrive.