Bit Tech has a quick primer on Nvidia's SLI XE motherboards. What's XE, and where does it fit in to the Intel line up from Nvidia? We have the low-down, as well as some info on SLI and Yonah / Core Duo.
"XE is an updated version of the original SLI chipset, and is designed to occupy the mid-range of Intel SLI systems. Between the nForce 4 Ultra (entry-level), the nForce 4 SLI XE (mid-range)and the nForce 4 SLI X16 (high-end), NVIDIA aims to have all tiers of Intel systems covered. The idea is that if a system builder is putting together a new range of systems for customers, it could feasibly use NVIDIA motherboards top to bottom."