I think that the only answer supported by facts is suspiciously absent from the poll. That answer is, of course:
Yes, whenever WotC feels like using it to issue errata.
I say that this is the only answer supported by facts because, as people have pointed out on this thread, there are instances where the errata files supersede the FAQ (i.e., they have been incorporated into the RAW, rather than the FAQ answers) and instances where the reverse is true (i.e., instances of FAQ answers being incorporated into the RAW, rather than the solutions presented in other errata files).
The
facts say that official rules have been culled from both sources, not exclusivley one or the other. In short, the argument that either the errata file
or the FAQ supersedes the other is pointless - because they
both supersede each other where different rules are concerned. And you can thank Wizards for that. When they chose to draw official rules from both sources, but not exclusively from either, they spawned this argument.
The truth is that little bits and pieces of the FAQ supersede rules presented in other errata files and vice-versa. Neither body of work is
wholly official, but bits and pieces of
both the FAQ and other, contradictory, errata documents
are official. What a mess
