In finishing up my first update on my treatise (see posting here), I came across a point I had meant to discuss but forgot; I forgot because it is an issue one rarely encounters and for good reason: the issue is so outre that when one hears it, you say, "huh?" It is one of those questions that as an associate you dread: a partner comes and asks you to research an issue that you never thought of because you can't imagine anyone making the argument; these are the worst type of issues to research, much like finding a case that says the sun really does rise in the East and set in the West.
The issue is this: when a court grants a motion to transfer pursuant to 28 U.S.C. Section 1404(a), whose law applies, the law of the transferring court or the law of the court to which the case has been transferred? In an entirely federal field of law like copyright, there are nevertheless issues on which the circuits diverge. In Auscape International v. National Geographic Society, 409 F. Supp.2d 235 (S.D.N.Y. 2004), Judge Lewis Kaplan did the equivalent of a judicial double take at the argument that because the case had been transferred to him from California, he was to use the Ninth Circuit's interpretation of copyright law, in particular that circuit's insane opinion in Silvers v. Sony Pictures Entertainment, Inc., 330 F.3d 1204 (9th Cir, 2003)(later reversed en banc, 402 F3d 881 (9th Cir. 2005)), permitting assignment of the mere right to sue.
The law is clear: the court to whom a case is transferred in a copyright case applies the law of its own circuit.