"A week or two ago The Compact Flash Association announced a new for*mat to replace CFcards for professional photographers, and HDLSR filmmakers. The new format is called XQD, and has a physical size that falls between CF and SD cards (it is thicker than SD cards, but smaller than CF cards). The interface used is PCI Express, with real world write speeds around 125MB/s, eventually being able to exceed 2 terabytes of capacity."
Read more from blog writer/canon consultant/photographer Eduardo Angel:
Meet the XQD Memory Card. Works with Nikon D4.