Great article! Just wanted to add that in addition to (sometimes in lieu of) taking a backup of the database before "experimenting", I often shut down SQL and make a physical filecopy of the MDF/NDF/LDF files. If something goes wrong, just move the copied files back overtop of the originals and you're back in business.

Yet another reason to make sure you back up everything *before* upgrading SQL -- even for a service pack install.