The lawsuit focussed on "orphaned" works for which it was deemed impossible (or, depending upon the audience, impracticable—the plaintiffs weren't very consistent) to find the copyright holder to obtain permission. Its stated concern was preservation of materials on deteriorating media that are not otherwise available in public distribution. Oh, you noticed the disjuncture there? I did too; so did a number of writers' organizations; and our concerns were blown off during polite correspondence with some of the suit's proponents. The problem is not the permission to make an archival copy, which is pretty well protected under copyright law as it stands today. That would fulfill the "legitimate cultural and scholarly interests" in the lawsuit—so long as scholars can travel to the archive, or even borrow a copy on a library-like basis, the material has been preserved and not lost. What Kahle et al. wanted, though, was something more like trademark than like copyright: Upon "abandonment," they want the right to distribute those archival copies on their own terms without permission from or compensation to the copyright holders.
By effect, what Kahle et al. wanted to do was an end-run around both Eldritch, which determined that extending the copyright term from 28 years with a 28-year renewal to a unitary term of either author's life plus 50 (later raised to 70) years or 75 (later raised to 95) years from publication for certain kinds of works was within Congress's power. I believe these terms are, in substance, too long, particularly for materials not the property of natural persons. However, as the Court said, determining the exact terms is within Congress's authority; and the only place to deal with "stupid" decisions by Congress is in the voting booth. (Eldritch never reached the treaty issues, but they would have torpedoed a win on the statutory question presented.)
Kahle et al. do have a legitimate point, in one respect… but the relief they requested bears little resemblance to it. Many works that are not owned by their natural-person creators—especially sound and audiovisual recordings—do have difficult-to-discern chains of title that often lead into the black hole of business dissolutions. What this argues for, though, is a change to the work-for-hire doctrine, coordinated with changes in the Bankruptcy Code. One such solution might be to transfer the default ownership of copyrights to the Library of Congress in any business dissolution that does not explicitly provide for a transfer consistent with the Bankruptcy Code, perhaps to be held in trust for a later legitimate claimant whose interests were not protected. But that's not what Kahle et al. requested as judicial relief; and that also assumes that any court would have the power to grant such relief, which is essentially legislation.
In the end, Kahle et al. wanted to be able to charge for copies of materials they archived without regard to the copyrights in those materials, on the unstated ground that their efforts at preserving culture deserve compensation. The American Film Institute's preservation efforts; and the Library of Congress's preservation efforts; and many museum preservation efforts; and more other preservation efforts than I care to describe manage just fine on academic grants. Certainly, there should be more money available for such efforts; but that is exactly the kind of prioritization that is in the legislature's province, possibly to be supplemented by private efforts. There is a huge distinction between making an archival copy and distributing copies of that archival copy. Judge Chesney, albeit on a somewhat less explicit basis, understood that distinction and properly dismissed the lawsuit.