Sergio calls my attention to this story from a few weeks back about the use in an Anthropologie store in downtown Seattle of some work that looks a lot like a work created by a couple of artists and shown at a Portland, Maine nonprofit art space called The Map Room in 2005. (There are pictures of the two works at the story link.)
One of the artists is quoted as saying, "We had no rights because the piece that we did was in a nonprofit context," adding that if his work "had worn a pricetag and shown in a commercial gallery ..., [then] the artists could sue for copyright infringement."
There's a technical legal term for that: crazy talk.
There's absolutely no distinction for copyright purposes between works created and shown in a commercial gallery and works created and shown in nonprofit spaces (like, say, museums). Now, there may well have been good reasons for concluding that a lawsuit wasn't worth pursuing here, but it's simply not the case that this work was somehow ineligible for copyright protection because it was done "in a nonprofit context."