Hmm, the point of doing this isn't clear to me.

It takes about the same amount of work to attach something to the correct FAQ as it does to post a reply pointing to the FAQ. So it's the same amount of work for us.

The poster gets a message instead of a reply. That's pretty much the same for her/him, too.

Meanwhile, the FAQ loses value by having worthless reiterations of the same question attached to the end of it. This may decrease the number of root postings, but I think it increases the noise. I don't see the problem as where the nodes currently are (since they can be easily eliminated from a search, or avoided in newest nodes), but rather the fact that they exist. Therefore, the problem, as I see it, is how to get people to look for answers before posting. It's a long-standing problem and I'm not sure there is a solution.