ASUS has leaked some pictures of a concept motherboard they will be showing off at CeBIT this year, the Marine Cool.
Little is known about the board but some assumptions can be made from the pictures. The board has dual PCI-E x16, x1, and legacy PCI slots as well as two SO-DIMM slots for memory. It seems quite odd that a motherboard that would clearly be targeted towards enthusiasts would resort to utilizing SO-DIMMs despite the lack of space required to implement them.
The bottom of the board has a unique micro-porous ceramic backplate that is said to provide better cooling and improved stability.