well i know she met the people who did the video - the mwc said on the website that the submitted video was now the "official video", but who knows.
nowhere has it been confirmed that wanderlust is the next single - the video was shot this month, while declare independence was done quite a while back (in may, i think). so i imagine wanderlust will follow after declare independence.
selmasongs was her vision for the music. the music that actually appeared in the movie was tweaked by von trier - part of the reason there was tension between them.
the webeo was hyped for so long because a lot of people didn't see it. those of us who did tried to warn everyone that it wasn't actually that interesting. it was designed to be "interactive", but with year 2000 internet you basically moved a bubble around pictures of her. similar things exist for pagan poetry and cocoon, i think.