Never! Stop dreaming mate!! Ethereum is a good project but catching up with bitcoin's price in the future is a whole lot to ask for. Sure, we can all say we do not know what happens in the future, but there are somethings that can never be possible and this is one of them. Bitcoin is more than established to get pushed out and even if other coins stand the chance of doing it better, bitcoin will always have that first movers advantage in looking at ways of changing some protocols to always make things better in the long run.