It's clear that a huge advantage has been lost, but it's not over yet. The teams have three more games to play. Dortmund still has a chance, considering that Bayern will play with Leipzig and Dortmund will only play with mid-tier teams. What they have to do to use it is to win all 3 games and wait for Bayern to lose points. The sensational result of 6-0 today also shows that Dortmund is still in this race psychologically. Last week's Bochum match draw was very hurtful for them, but there is still hope.
The 6-0 doesn't change that much I think. If it was about the goal difference in the end then yes, but Dortmund is too far behind to make that count eventually. Yes psychologically that was a good counter to Bayern's win yesterday, but Dortmund can play one game like this one against Wolfsburg and the next one they are catastrophic and nobody knows what's wrong with them. When I saw the result against Wolfsburg, I thought that really they could have done it this season, but it is not about the games when they score 4 or 5 or even goals, it is about the games when they lose points against weak opponents. Too bad.