So you go on a job where the homeowner wants to tap an existing outlet and install a 2nd one about 2 feet away so he can quit using an extension cord (because the last one had a poor connection and caused a little fire).
You arrive and find a 100 year old house, nothing is grounded but the neutral bond at the entrance, and every thing is protected by fuses. How much does it cost to extend that circuit so this home will be at least one step safer, and so the homeowner (who can't afford to replace the panel or rewire the house, much less both) won't have to keep using an extension cord (something the NEC seems to want to get rid of).
Of course one lower cost option can be a tiny 2-circuit subpanel right next to the old main with a couple of AFCI breakers in it.
How about this: submit a code change request to the NEC for 2008 (6 months remain to do this) that gets very specific about requiring AFCI whenever an existing non-AFCI protected circuit in a location that requires one is extended. They might accept it. Or they might refuse it and say the code already covers that. Or they might refuse it and say that this is not desireable. This could readily be a way to get an answer out of the appropriate committee (sometime over the next couple of years).
