The Tech Report provides some extra details about Intel's upcoming Xeon processors. The Haswell-based Xeon E3 series is expected in mid-2013, this family will offer TDPs as low as 13W! The new E5 series (Q3 2013) on the other hand is based on the Ivy Bridge-EP architecture, while the high-end Xeon E7 is based on Ivy Bridge-EX.
The E3 series will be limited to single-socket series, it offers up to four cores and 8MB L3 cache, with 20 integrated PCIe 3.0 lanes and up to 32GB memory support. The E5 on the other hand will offer up to eight cores, these chips are fit for dual-socket systems and will have 20MB L3 cache, 80 PCIe 3.0 lanes, and support for up to 768GB memory. High-end servers will get the E7 family with up to 10 cores, support for four or more sockets, up to 12TB RAM (for eight-socket systems), 30MB L3 cache, 144 PCIe 3.0 lanes and TDPs of up to 130W.