All manufacturers exposed at least one motherboard based on Intel's future high end chipset, the X38. This chipset supports two real 16X PCI Express slots and, officially, DDR3 at 1333MHz.
Abit and Asus
Biostar and DFI
ECS and Foxconn
Gigabyte DDR3 and DDR2
Intel and MSI
If the standard configuration includes two slots 16X, several manufacturers (Abit, Asus, Biostar, DFI, Foxconn and Intel) have added a third one in 4X. MSI has chosen a more complex design with two 16X slots and two 8X supported by an additional controller. We don't know yet how they communicate with the other components of the system.
The X38 will be a high end chipset and we thought that it would be only reserved to DDR3. This isn't the case. Abit, DFI, ECS and Gigabyte are selling a DDR2 models and Foxconn and MSI a combo model. The shuttle mobo designed for barebones is also restricted to DDR2 and of course only features on 16X PCI Express slot.