When I emerge azureus-bin 2.3.0.4 with -gtk in useflags you get the motif package, and it comes with libXm.so whereas the openmotif library needs libXm.so.2. revdep-rebuild confirms this and wants to rebuild azureus-bin which then still provides the wrong library.
revdep-rebuild doesn't work correctly with binary packages. Anyway, azureus-bin is deprecated, see Bug 113389.