Hi.
There's another argument I've forgotten to mention:
It may well be that "fair use" is protected in the USA, but that doesn't
mean
that some big nasty company can't sue the project. Many companies in the USA
use the legal system as a blunt weapon, without caring much whether they'll
eventually win or lose any given fight.
They'll have more money than we'll do, and they could take it as far as they
wanted.
Of course, in most cases like this we could simply remove the relevant images.
But that could be more of a problem for projects (educational, in the US) who
have printed or made CD copies of Wikipedia.
Also, we could be exposed to companies with an agenda, such as puppets for
encyclopedia publishers. Who knows, maybe the pure audacity of Wikipedia as a
source of Free information will piss of some of the bigger media conglomerates.
I say this counts in favour of staying away from non-free material, free use or
not.
-- Daniel