I hope the FIA decides it's time to quit playing around, and tells the teams "fine, no voluntary budget cap... A mandatory 44 million cap and that's the end of it".
You see, the problem is that the teams are complaining about this whole voluntary thing, while in reality they simply don't want a budget cap at all. Ferrari has the resources to win, just as Renault does and Red Bull... If there's a budget cap all those resources won't help them, and they will need other means to win instead of 'more money'. Ferrari has proven so far this season that they seriously lack other means to win. They aren't in F1 to compete for the win, they're in F1 to buy themselves the win.
Teams should quit complaining... This budget cap thing ultimately will save F1, even if the big teams leave. As long as they remain the fastest cars that run on road courses they will be F1.