The Tech Report writes Gigabyte will release two new thin mini-ITX mainboards this month; the GA-H77TN and GA-B75TN. Both models have an LGA1155 socket, four USB 3.0 ports, four SATA ports, dual SO-DIMM memory slots, an open-ended PCI Express x4 slot, and two Mini PCI Express slots that can be used for a SSD card and a WiFi card.
In an all-in-one system, the display will be hooked up via an onboard header, not through the outputs in the port cluster. Of course, Thin Mini-ITX doesn't automatically imply all-in-one—there are also ultra-thin traditional cases based on the standard.
At a glance, the only notable difference between the GA-H77TN and the GA-B75TN (beyond the fact that they're using different platform hubs) is that the former has two 6Gbps Serial ATA ports (colored orange), while the latter's SATA connectivity seems to be limited to 3Gbps. This appears to be more of a product segmentation move than a platform limitation. A look at Intel's spec sheet for the B75 Express suggests the chipset does have native 6Gbps connectivity.
These models are mainly intended for the embedded market, and feature add-on risers with COM ports and support for both 12V and 19V input voltages.