MSI's Z77 motherboards are engineering version, not final design ones. They have two on display, the mid-range Z77-GD65, and more high-end Z77-GD80.

The Z77-GD80 can house two graphics cards and has a 14-phase VRM for the CPU. There are three long PCIe slots on the board, two slots are PCIe 3.0 capable. Ther are four 6 Gb/s SATA ports, USB 3.0, Intel Thunderbolt, and monitor connections that include DVI, D-Sub, and HDMI; 8-channel HD audio, GbE, and eSATA.

 The Z77-GD65 is the more mainstrem version and comes with a 9-phase VRM for  the CPU, it has two PCIe 3.0 x16 (x16/NC or x8/x8), one PCIe 2.0 x16 (x4, wired to PCH), and four PCIe 2.0 x1. Its connectivity might lack Thunderbolt.

MSI also is showing GUS (graphics upgrade system), an external graphics card enclosure. This box connects to a host PC/Mac using Thunderbolt (essentially PCIe 2.0 x4), and internally has a PCIe x16 slot and related power delivery circuitry. It draws power from an external source. We've seent hese things in the past and the latency always has been an issue. But I'm sure we'll test it when ready though ... photo's are courtesy of HWC.