This is a good article. I can see why it was reprinted. I'd like to see an update. Things are just a little different in 2005/2008. Those differences, some of them cosmetic, such as the change from bookmark lookup to RID lookup in the execution plans, would change some of the details of the article as well as some of the methods of correction (INCLUDE has been mentioned several times).
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning