Well, here's what Niklas said in the DT DVD -thread a while ago:
"Yes, the Wacken show was supposed to be our first real live CD and DVD, but as you know that fell though because of stupid scheduling misunderstandings... We don't really have much video material recorded, so a DVD release in the near future isn't very likely. But something will probably happen sooner or later."
So, perhaps someday there will be a live DT-album, but as people nowadays also want to SEE the show, it must be on DVD. And for that we need to wait.
-Villain (Dr. Tranquillity at your service)