I'd call this "Disk Management 101", in that it covers the basics.  I'd say the majority of the people in this forum already have implementation plans for storage capacity planning.  I was personally really hoping to see more about External Capacity...  can we expect one of those in the future, too? 

Given the above, SQL Profiler, and a good trace template, I have found it quite easy to point out Internal (SQL-object based) performance problems.  But what about those problems not associated with I/O?  Is it a Network Problem?  Client problem?  I have theories about the problems that I have encountered over the years (like if MS Access is running a query and the CPU is pegged, then leave me alone ), but what if it isn't Access?  How do you work with your network team to find the problem?

I am a firm believer that network n0mes don't exist.