Basically, 10% was used more as a rule than a guideline, but applied equally to edited collections as well as single-authored books; multi-semester use of materials is allowed; and only 95% of the instances brought before the judge were determined to be in violation of Fair Use. However, the judge also seemed to think that we (potential infringers that we are) should determine monetary effect of our use, even when that information is not available to us. I think. Or something like that. Anyway, read it for yourself and see what you think.
Libraries can not (yet) breathe easily, but at least they're not (quite) dead.