The Tech Report came across two photos of a Socket FM2 desktop motherboard for AMD's Trinity over at VR Zone.
The board is actually a prototype, apparently from MSI, and the size and shape suggests a DTX form factor. Around the socket are four DDR3 DIMM slots, a four-pin CPU power connector, a PCI Express x16 slot, and three PCIe x1 slots. I can see four SATA ports hiding under some cables, too, and a VGA output in the port cluster.
As for the socket itself, the writing on it reads "Socket FM2." Since desktop variants of Llano fit into FM1 sockets, we may be looking at a new pin layout—but perhaps backward compatibility has been preserved nonetheless. (AMD's Socket AM2 processors do work in AM3 and AM3+ sockets, after all.)