Mike Masnick over at Techdirt highlights some interesting musings from the Copyright Office which suggests a slowly shifting emphasis on how to determine Fair Use (a legal test which is notoriously slippery and can be bent in many cases to suit any preconceived result a judge wants to reach ahead of time):

http://techdirt.com/articles/20100804/04102010491.shtml

Hopefully, this will signal a (too slow and small, but still valuable) move away from the very disingenuous "market" test, or the effect of copying on the work's "value". This factor is almost always applied in a fraudulent manner since many courts don't only consider the markets which currently exist, but also potential future markets that the original author could potentially exploit. This becomes a tautological argument since the author can ALWAYS say that he/she intended to exploit a new product market in the future, even though they made no steps to do so in the past. Under this scenario, any copying of a work in any context becomes a per se harm to some hypothetical market which might exist in the future.