What the wonderful ending meant to me (Spoilers)
First of all, I don't think it's productive to frame this discussion in terms of what the story means, what the director meant, etc. I think for those who came away intrigued by the movie and its ending, the more important thing is ask - What did it mean to you? What did you take away from it? How do you feel about it?
Okay...we watch Mr. Badii as he interacts with 3 men of different backgrounds. They can also be roughly said to represent 3 different institutions as well. The state, the clergy, and the final man discussing nature and the simple joys of life (or perhaps he can be said to represent wisdom and experience in general.) None change Mr. Badii's mind, although we sense the last man has some influence. In fact, not even Mr. Badii seems to know the answer, as he seems to be at least somewhat conflicted at the end even as he continues with his original plan.
When suddenly the film crew and the director appear, I was struck by the sense that they were an additional party trying to make sense of life, trying to find meaning or solution for Mr. Badii. As if Mr.Kiarostami himself was on this journey the whole time as well, trying to work things out or understand.
Thus Kiarostami represents the artist, in the same way the other men represented other approaches to life. And it seems at the end no one has a clear-cut answer, as we don't even know if Mr. Badii lives or dies, or if Kiarostami himself can wrest some meaning in a final outcome to his story. The end sequence was quite a shock when I first saw it (what is happening?!?), but somehow felt very relevant at the same time, I think this is why.