If using two dual slot cards, you still have two PCI-E 16x slots and a normal PCI slot left for soundcards or whatever else.
You can use up to two dual slot cards with a PCI or PCI-E soundcard, 3 Dual slot cards with a PCI-E soundcard (placed in the third 16x slot), or up to 4 dual slot cards in a full tower case providing the I/O panel of the last one is only single slot.
If this kind of slot layout existed back when I got my X58 UD5, I could have kept my X-Fi Elite Pro. I wont be getting a PCI soundcard again because finding a decent motherboard which can hold two GFX cards and a PCI sound card is nearly impossible, but up to three GFX cards and a PCI-E soundcard is brilliant too.
Not only is the slot layout perfect, but the overclock features are top notch too - Extra power for the CPU and PCI-E lanes, easy Bios flashing with a USB stick if it corrupts, and the optional extra air cooling for the X58 chipset.
I didnt buy such motherboards before because there was always something missing for the price tag, but I cant fault this one, and thats the first time ever that I cant fault a motherboard, the only thing I can see so far that people might not like is the appearance and heatsink design, but I like that too
Actually, there might not be enough space for my Asus Triton 88 to fit with the chipset heatsink so close to the CPU socket, I'll have to email Asus support about that to check.