The Intel® X38 Express Chipset is the latest chipset designed to support 8GB of dual-channel DDR3 1333/1066/800 architecture, 1333/1066/800 FSB (Front Side Bus), Dual PCI Express 2.0 x16 graphics and multi-core CPUs. With the specially included Intel® Fast Memory Access technology, available memory bandwidth usage is optimized and memory access latency is reduced - allowing faster memory speeds.
It even supports 1600MHz CPUs (the X38 doesn't officially support them, that's what the X48 is for, but ASUS have released a BIOS update which enables support for 1600MHz FSB)
In short, it supports all the LGA775 CPUs.
@ Remeniz, glad you're happy with the case. Again, I'm really really sorry about that scratch.