Much discussion has been generated by Roy Grenslade's comments on why sub-editors are becoming redundant.
He makes a very clear and coherent case for when they are required - on pop papers where their creativity is a vital part of the finished product.
Apart from that, they are fast becoming a luxury.
As Greenslade says, he doesn't need a sub to get his blog published.
What he also doesn't need is an editor.
No proficient columnist does. Nor do experienced, specialist reporters.
So, let's take it as read that the sub is dead in the multimedia world. Now lets move on to considering when an old-world editor might still be necessary. Rarely, is the answer.