Current copyright law grants the author rights to any/every work created (including finished pieces, paintings, sketches). Copyright is inherent at the moment of creation. You can register work with the Library of Congress (http://www.copyright.gov/forms/) to give you more air tight rights, but it's not necessary.
Now meet the Orphan Works Bill. If it passes as described in the video below copyright won't be granted to the author until they register each work. This will be very harmful to every artist / musician / creator and helpful to large corporations.
So any work that the artist doesn't register can be taken and used by anyone else as an orphan work. Do non artists realize how many images and how much content artists actually do create? Take a look in any sketchbook and you'll find thousands of unique images that belong to the artist. Should I keep my sketchbooks and artwork in a safe so I'm not robbed by Disney or Google of my intellectual property (or anyone for that matter?)
The Orphan Works Bill will eliminate the need for any person or organization to license unregistered work. Say I'm publishing a book and I want to use a painting for it's cover. If it's not registered I can pluck it. I know there's a generous handful of people out there who would like to use artwork for free and would do so over paying for it if they had the chance. What's to say they won't just avoid registered work in favor of trolling for orphan works they can use for free? When it comes to the budgetary bottom line cheap and free reign supreme.
It's all up for grabs. Look out world.