My 2 cents.
The FAQ is a few guys over at WotC who tend to rule as a DM at the table. They make a quick ruling which may or may not follow RAW, but which they appear to think does. Often it does. But, not always.
There are quite a few "mistakes" in the FAQ which obviously directly disagree with what is written in RAW.
For example, I think they have Mirror Image work as they want it to work, not as it is written to work (i.e. images are not creatures, hence, cannot be affected by Cleave or Magic Missile, or Blur spells).
An errata to allow for this type of thing should be put into the Mirror Image spell and state: Treat the images as creatures for purposes of feats, spells, and other effects.
Problem solved.
Instead, they just write in the FAQ that you can do all these wonderful things to images AS IF they were creatures, but they are not.
Ditto for the Acid/Sonic issue and several other issues.
What WotC should do is keep up on their official errata. If they did that, then any FAQ answer that disagreed with RAW could be "clarified" in the correct manner.
Not by adding a change of the rules to the FAQ where it does not belong.
