Since tomorrow is May 1, I think it is time to publish the latest set of SQL Server 2008 Diagnostic Information Queries. This version works on SQL Server 2008 and SQL Server 2008 R2. There are a few queries that only work with SQL Server 2008 R2 SP1, but they are noted in the comments.
Many of these queries are DMV queries that require VIEW SERVER STATE permission. Make sure to read the instructions before you run each query. You really should run these queries one at a time, and take a few moments to look at each set of results, rather than running them in a single batch. Much of the value of these diagnostic queries is in the result interpretation comments after each query.
I have fixed a few minor issues with this version, and added several new queries. Please let me know what you think!