No that can't be..Dollar is well established currency with strong support from the people not just from US but all over the world..Though we know that bitcoin is going to be stronger this coming years, it still can't beat dollar...
Even if it can that should not happen. There will be a lot of chaos in the world if this happen. A lot of people own dollar so how can you expect the, to give this back through the means of bitcoin. Will bitcoin be enough for all the people that own a dollar? Every single penny should be changed through this currency and that is like an impossible thing to happen.