My main concern is that any Tom, Dick or Harry can come along and 'claim' to be a sculptor. There is becoming a serious downfall in the lack of the basic skill sets (not just for sculpting) and this type of technology, although useful, is helping this to happen at a quicker rate.
My other concern is the 'quick' demand that it causes. I see this all the time in my industry, things get wanted on a faster and faster time frame and the quality is reduced somewhat because of it.
Sculpting is a real skill and you have to have a knack to be able to do it properly and as I mentioned before, the skill base is being reduced 
well, if we are dragging the old topic up again...
I've reached a point where I can call myself a professional 3d artist/sculptor/whatever, and I fully agree with Jim. 3d work has a lot of advantages over hand sculpting, but just as many downfalls. The computer game industry is a poor source of material since they tend to use simple sculpts with detailed "skins" over them, which don't translate to details on a print. On the other hand most of the "problems" we are currently having with 3d design and printing aren't inherent to it so much as to the market as a whole. I think that if instead of 3d printers we had gotten super cheap and good no hassle mould making machines we would have been in the same situation, average Joe without and sculpting skill buying them in the hope of producing miniatures, the "quick demand" principle Jim mentions would be in full effect there as well.
Just my 2 cents from the other side of the fence,
Cheers,
Tim