I've been working on some whitepapers on scaleout technologies in SQL Server 2005. The first whitepaper is now available; I don't have the main link, but here is the direct link to the doc file on the Microsoft download site. The whitepaper is about the implementation steps when using scaleout technologies like Service Broker, Scalable Shared Database, Query Notiifcations, and Peer-to-Peer Replication and how to choose which technology or combination of technologies is the best fit.
It will be followed by a companion whitepaper about internals and troubleshooting of these same scaleout technologies. I'll let you know when that one's available. Hope you find them useful.