Here is the summary and the link to the white papers.
Working with TempDB
This white paper describes how SQL Server 2005 uses tempdb. Many improvements in SQL Server 2005 optimize tempdb usage and make it easier to manage and to troubleshoot. A case study that uses a workload similar to TPC Benchmark H (TPC-H) shows new ways to manage and troubleshoot tempdb resources. This paper also includes items to consider when upgrading to SQL Server 2005 and configuring tempdb
Physical Database Storage
This article provides a guide for physical storage design and gives recommendations and trade-offs for physical hardware design and file architecture.
These papers will soon be available on TechNet as well.