I've noticed that, as more companies want to run SQL Server applications 24x7x365 interest of clustering has increased dramatically. One of the most asked-for papers about SQL Server 2005 is an update to the clustering whitepaper. Well, its available NOW; an over-100 page treatise by Allan Hirt and Dave Whitney. It covers not only clustering SQL Server 2005 but also Analysis Services 2005. A MUST read. Look for "Failover Clustering for Microsoft SQL Server 2005 and SQL Server 2005 Analysis Services" at Microsoft download site.