I haven't been able to access the Sims 3 site since before I went to work, so several hours. If they are dealing with some sort of technical meltdown it might explain why they've been slow to deal with this. But I have to think that they will eventally remove it, if only to get a break from all of us reporting it.
I did report it as well. I know it isn't even close to the same scale, but I worked for a long time on my Cold Glass house of Water, and I would be pretty upset if someone claimed that work as their own. I think that the fact that there isn't a profit motive here actually makes it worse. The only reason we have to share our work is our sense of pride in what we've made, and it's pretty pathetic for someone else to try to claim that source of pride for themselves.