bonissent,
I hope by now you have purchased a great board, but I post anyway for others who might read this thread.
I don't have a fantastic sense of which chipsets are overall "better," (Intel or AMD), but I myself prefer the Intel X38 chipset because of its vastly improved memory controller.
For Motherboards, I am a recent convert from Intel to ASUS. I have a Maximus Formula, with the X38 chipset. I have about 8GB [tested] bandwidth to my CPU, and that works well for large data-set operations.
In the end, what matters probably above all else (including brand loyalty) is just that you get something with PCIe 2.0 support. The "2.0" part is very important; chipsets only recently started adding this support, and the 3xxx line of GPUs are some of the first to use it as well. In most of my GPU work, the PCIe bandwidth is the bottleneck, so the 2.0 was important.
One last consideration. A board with multiple PCIe 2.0 slots might be good, because you can easily drop in another board to improve performance (Crossfire, or custom coded). Most ASUS boards are so equipped.
Regards,
Scott