Apple has introduced a whole new Mac line up, including a 13-inch Macbook Pro with Retina display, iMac, and Mac mini. The 13-inch Macbook Pro is second only to the 15-inch version in pixel count, starting at $1699 and shipping today. The iMac is a remarkable 5mm thick, coming in 21.5 and 27-inch models, with new display technology that bring pixels closer to the surface.