If you haven't read the latest CEA Update, I'd suggest taking a look at it before you e-sign anything. I'm petitioning this revision because I think it's opening a door that will ruin this community.
Allowing members of deviantART to copy, trace, or duplicate any copyrighted artwork is giving a mixed signal to growing artists. Whether or not it's done with the intention of practicing, the act of submitting it into an official gallery here on deviantART is copyright infringement.
If we would penalize these same deviants for copying an artist within the community--who discovers it and complains about it--then we should be penalizing them for copying all artists, as all artists have legal rights to their works.
Having the practice works moved to their own little area of deviantART could be tolerated, but having them in official dA galleries is offensive. We are an art community, originality is what makes art amazing. Don't let dA become an image hosting site by allowing copied, traced, or duplicated artworks to be displayed among the sensational works of original art.
The News Article: CEA UPDATE 20090130; Issues Involving Copying
Petition: deviantART: Crack down on Copyrights