Nice article, but I'm missing a hint to adhoc queries and their influence on the proc cache. You can save a lot of memory by using the optimize for ad hoc workloads Option.

http://msdn.microsoft.com/en-us/library/cc645587.aspx

For more details see this blog entry from Kimberly Tripp:

http://sqlskills.com/BLOGS/KIMBERLY/post/Procedure-cache-and-optimizing-for-adhoc-workloads.aspx