Mercedes's costumer team won't have any chance because Merc won't give them the best material - Williams only got the best electronics package in Austria this year.
Red Bull and Ferrari will have a hard time to find such a leap, in fact I can't see them finding about 40 horsepower over Merc.
McLaren-Honda is a question mark, but Honda might lack of experience while the three other engine manufacturer have a year of experience in their pocket.