Bayern Munich is still best club in Bundesliga even though they lost to Leverkusen. They had some ups and downs which allowed Leverkusen to take the lead. But I think Bayern will come back stronger next season because they learned from their mistakes. A big club like Bayern won't give up after one bad season.
Of course people have a high expectation on Bayern Munich next season and I believe they will deliver very well irrespective of there lapses this season, concerning there performance this season most people believe since they perform the way they did they will be able to win the Bundesliga next season but for me I don't actually see it that because although indeed there performance was bad but is very normal for a club like that because there is no way a particular club will be wining the trophy all the time because is not going to be fun, the fun in football is when there is a serious challenge between all the clubs, perhaps that's the reason why premier league is one of the most interesting league because it will be very difficult for a particular team to be wining the trophy for several seasons without being intercepted by other teams.