In the lead up to the PDC every year, there's always some amazing work done as Microsoft prepares to show some of its customers what it is we've been up to lately. The Routing Service has (fortunately) been included in some of the discussion and demos, so I thought I'd point them out.
The primary point for all of what's new in WCF in .NET 4 is Ed Pinto' talk at the PDC, which should have a video posted over here in the coming days. In the meantime there's a slide deck of his talk, which touches not only on the Routing Service but also on all of the other improvements we've made throughout WCF, such as configuration simplification, the addition of WS-Discovery (which I'll show you a sample of linked up to the Routing Service), and how Dublin (the team I work on, now a part o the AppFabric) can help make managing and monitoring your WF and WCF apps easier.
Another interesting PDC-leadup project was put together by a friend of mine Dana Kaufman, who works closely with the M/Oslo (now SQL Server Modeling) group. One of the black eyes of the Routing Service that I'll get into at some point (and we have a few) is that we lack any sort of tooling for authoring Message Filters, Message Filter Tables, or tweaking any of the other knobs. The customer (you!) is left on your own to determine what those tools look like and how they work. This is hopefully something we'll fix in later renditions, since, frankly, writing complicated message filter logic can get complicated. Dana's project is an excellent example of set of Routing Service controls that happens to take advantage of the formerly-Oslo technologies to do the work of creating Message Filters. You can find the blog post that describes the project (Model Driven Content Based Routing) here, and they've also posted the code for everything out at the MSDN code gallery for you to peruse.