We snapped a couple of pictures of a pair of AMD 790FX/790X boards when we visited Gigabyte a couple of days ago and although these boards are already available, there's at least one interesting thing worth pointing out.
The GA-MA790X-DS4 board has a very odd looking second PCIe x16 slot, as it will physically accomodate a x16 card, but it doesn't have the full pin-count inside the slot. Due to the chipset limitation of supporting only two x8 slots, there's no need for the extra pins, as they won't be connected, anyway.
This is aparently a way that the component manufacturers have realized they can cut some material cost, and in the end this lowers the cost to the motherboard manufacturers. With regard to power concerns, there aren't any, since the additional pins wouldn't have been connected to anything either way.
As we mentioned earlier, the only real difference between the GA-MA790FX-DS5 and the DQ6 is the fact that it lacks two of the additional x16 slots, but as the layout of the board would have prevented the usage of a dual slot cooler, this might not be an issue for most people.
The board also lacks the slightly more advanced heatpipe cooler and one Gigabit Ethernet interface. However, it is a far more affordable option and we think this will sell better than the DQ6 version.