The Intel SSD 910 is a triple-layer stack of NAND chips that fits into a single PCI-Express slot. The drive will be available in both a 400GB and 800GB flavors, with the 800GB version offering higher performance thanks to a greater number of on-board controllers.
Here's the exploded view of the three layers on the 800GB version. Each of the four ASICs visible on the lowest section of PCB controls 200GB of NAND. Communication between the four controllers is handled by the PCI-to-SAS (Serial Attached SATA) bridge chip hiding underneath a heatsink. Communication between the NAND ICs themselves and their requisite controllers is provided via a 60MHz ONFI 2.0 interface, as shown below:
Intel has employed LSI's PCIe to SAS controller and there's plenty of bandwidth for the card on the PCI-Express side of the equation; a PCIe 2.0 x8 connection is capable of providing up to 6.4GB/s of useable aggregate bandwidth. The 400GB drive is configured identically as the 800GB pictured above, but lacks the second set of NAND controllers.