Leveraging the Nehalem architecture that was first launched as desktop Core i7, a raft of new Xeon chips are in the offing. Dubbed the Xeon 5500-series, retailers are already listing the 2P-capable chips on their online sites.
For example, you can buy a quad-core Xeon W5580 - which operates at 3.2GHz, has 8MB L3 cache, QPI running at 6.4GT/s, and on an LGA1,366 form-factor - for the princely sum of $1,678, plus taxes. The main difference between it and the desktop Core i7 965 Extreme Edition is the presence of two QPI links in the server part, to link in with another chip in a two-processor setup. That and official support for DDR3-1,333 memory, most likely.
We expect other 5500-series processors to flesh out the new Xeon line, also known as Nehalem EP, to form a top-to-bottom launch. Knowing the form-factor, it's reasonable to assume that the initial batch of chips will sit on a Tylersburg chipset with a couple of IOHs (input/output hubs).
Lastly, expect the official releases to start cropping up at the end of March, as that's when Nehalem EP is officially released.
Personally, I'm far more interested in the eight-core Xeon on top of a Boxboro-EX chipset, but that's likely to surface later this year, if at all.