Opensourcing the code is different from including music or graphical assets that are licensed. The Bink issue is legitimate, yes, but there's nothing stopping them from stripping copyrighted assets from the game prior to opensourcing. Harmonix's source for Guitar Hero II on PS2 would be nice to see in such a form, for example (and their engine is pretty much entirely bespoke, so no real worries about license incompatibility). Along with the necessary tools to build our own assets (that we can't already do with homebrew tools).