MSI is teasing its upcoming Z170 series motherboards. In the picture below you can see three Gaming M series LGA1151 motherboards with DDR4 support. The lineup includes the Z170A Gaming M5, Z170A Gaming M7 and Z170A Gaming M9 ACK.
One of the new features on this lineup is Reactive Armor, a backplate that promises some shielding for the electrical components as well as extra (physical) stability. You can see the Reactive Armor in the right corner of the image below, the CPU area has a cut-out so the backplate doesn't make it harder to install a CPU cooler.
We also hear MSI will be incorporating LAN Protect on the Gaming M series, this feature was already present on the X99A Godlike Gaming motherboard and protects your system from overcurrent over an Ethernet cable (like in the case of a lightning strike).
The Z170A Gaming M5 offers all the features you need to build a slick gaming PC build, with up to two high-end graphics cards. It offers a 10-phase CPU VRM, an all-PCIe gen 3.0 expansion area, ten SATA ports (including two SATA-Express 16 Gb/s), two M.2 slots (both 32 Gb/s), and AudioBoost III audio, with Killer E2205 GbE.
The Z170A Gaming M7 takes things a notch up, with a 14-phase CPU VRM, a "Game Boost" rotary knob that steps up CPU and memory clocks in 11 preset steps, and better onboard audio.
The Z170A Gaming M9 ACK leads the pack, with a back-plate, liquid-cooling preparation for the VRM heatsink, and Killer ACK WLAN. All three feature USB 3.1 with both type-A and type-C ports.