The Inq claims Intel's X58 based enthusiast motherboard will be called DX58SO:
The specs remain the same, ATX form factor, LGA 1366 socket, 3 DDR3 channels and ICH10R. The -R suffix adds RAID with " Rapid Recover" technology, but the rest is the same as the ICH10 on the G45 and G43. There will also be configurable PCIe2.0 lanes, either 2x16 or 4x8, take your pick.
Sources tell us that the the SO in DX58SO stands for 'Significant Other', something that the target demographic sees their high end gaming box as.