Honestly I didn't have any expectation from Dortmund to beat Freiburg in an away game. Their performance last week made me doubtful about them for this game. However they still managed to win this very tough game. And they did this by scoring three goals in the last fifteen minutes of normal time. Dortmund are still a very interesting team. It is hard to predict what they can do in this kind of games.
It is nice to see them winning vs a hard opponent so they won't let Bayern fly alone with the title since the beginning 
There is Leipzig that worth seeing if they could do something vs Koln and if Frankfurt will recover vs Hertha or they will keep bad results.
For Bayern they shouldn't have issues vs Wolfsburg
If teams like Leipzig, Leverkusen and Dortmund fail to play well from the start of the season, then we will see Bayern Munich's dominance from the start of the season. Leipzig should perform more cautiously. And securing 3 points against weaker teams. Otherwise they will be behind in the points table. Dortmund are top of the table after winning their first two matches. It's pretty good.