The crux of the problem is the fact that you needn’t register a work with the Copyright office, or even put the little “(C) Copyright 2005” mark on it for it to be copyrighted anymore, nor do you need to renew. A doodle on a napkin is just as copyrighted as a composition registered with the Copyright office (though you can’t collect damages until you actually register the work). So nowadays copyright isn’t even fire-and-forget — the gun can be still sitting on the mantle. Until that’s changed I’m not sure of a good way out of this morass.
Personally I’d like the current copyright rights only be enforceable for works that are registered with the Copyright Office, with the onus of the copyright holder to update his or her contact information in a timely fashion, and every so often to take active steps to renew the copyright. These shouldn’t be onerous steps — a simple form with little or no processing fee should be sufficient. If a work is not registered or renewed, or if it’s deemed impossible to find the copyright owner, then the either the work should fall into the public domain or possibly become protected under a much more limited set of copyright restrictions such as those provided under the Creative Commons Attribution License.