Working in the graphics area, and moderating it myself, as a professional artist, this is my perspective.
In the initial weeks of SOTW, and on other sites, we find that there are many members, of various skill levels who wish to join the SOTW. Week 2-x, the decline of the SOTW continues. As of the final week I find myself looking at low-intermediate to brand-new-to-photoshop style signatures spanning 4 submissions. I rejuvenated the SOTW weeks later for another try at it, seeing as the SOTW had boosted in requests. The same result - three or four submissions, and they all were low-inter to brand-new in skill level. It was decided then that, in my opinion, if Phil (Then 'Boomheadshot') and TDD did not lead a few (3-5 users) into some skill, the SOTW could not thrive and continue. I saw no progress toward this, so I stopped the SOTW all together. TDD tried to continue the idea, as I predicted, but no one wanted to accept his teachings, so the graphcs forum died shortly after.
I have seen a short revival in the area, but I will have to see it pan out before I can continue to see the forum have it's SOTW. Sorry.