Photos of the Intel X38 reference motherboard were published at the forum of an Asian site called Chiphell.
The motherboard features two PCI Express 2.0 x16 slots, a PCI Express x4 slot for an optional physics card, 2 PCI Express ports, 12 USB 2.0 ports, 6 Serial ATA ports. The motherboard also supports Intel's Extreme Tuning Utility which will offer a wide range of overclocking options and tight integration with the motherboard's BIOS.
The site also published some charts from Intel which indicate the X38 may be up to 10% faster in integer, 30% faster in floating point and have 60% more memory performance than the old 975X Express chipset.
Another new technology in the X38 Express chipset is Intel Extreme Memory, which seems to be Intel's response to NVIDIA's EPP memory technology.