In the past the removal of a failed Domain Controller wasn't that easy as it sounds. Just deleting the account in de Active directory wasn't enough, you had to manually remove the NTDS object. By using the ntdsutil utility and some cryptic commands you were able to remove the Domain controller.
One if the improvements of Windows 2008 was the inclusion of automatic metadatacleanup. So if you delete a domain controller using the AD Users and Computers snap in you have an option to remove the DC permanently and all metadata will be automatically removed. So there is no need to use the ntdsutil utility anymore. You probably won't use this every day but even then it is good that life is becoming more easy every day ….
