With ever more features integrated into modern CPUs, including the memory controller, motherboards have become less critical for performance.
Consequently, you'll find little to choose between various Intel X58 boards in terms of stock-clocked application performance.
However, when it comes to overclocking, the quality of features such as power phases can have a big impact. Likewise, in future SATA and USB bandwidth will be increasingly critical. SATA 6Gbps and USB 3.0 are now essential on any high end board.