I don't think he really lost the dressing room. If anything, he was not authorative enough; this team doesn't strike me as having a lot of difficult personalities to handle.
Hiddink just seemed to have lost his usual sharpness. In matches, he seemed to constantly chop and change, even after succesful games. He looked clueless. There was no stability to the team, and all Hiddink seemed to do was complain about the quality of the team. While this is not our best team ever, we still managed to end 3rd in the World Cup, so being in 3rd place in the qualification group is nothing short of a disgrace. In press conferences, he looked like a man with Alzheimer's, struggling to put together coherent sentences. I didn't expect him to fail this miserably, but he made us play so bad this year that Blind can hardly fuck it up more. Blind, though, is very inexperienced as a manager, so I fear we won't reach the level we could reach in EURO 2016, provided we qualify of course.
Then again, should we fail in 2016 or before, we could hire a better manager after the EUROS. De Boer and/or Koeman might be available then, while they weren't now.
Van Basten will be Blind's assistant, which is also a peculiar choice. Van Basten stepped down as the manager of AZ Alkmaar last year, as he felt he was not up to the job. He preferred not being the manager anymore, so he was voluntarily demoted to the role of assistant manager. Now, 11 years after starting as the manager of the Dutch national team himself, he will be Blind's assistant. Again, I think Van Basten, while being a football legend, is not a particularly skilled manager or assistant manager. He's just good friends with Blind, which is probably why he landed the job. Then again, he has some valuable experience as a manager of the national team. I would've preferred a more experienced, tactically qualified assistant though, although it's hard to think of the best option there.