With smaller players dropping out of the game, soon it might become a "single player" game after all. If this scenario happens, then a single entity controlling 51% of the keychain nodes can potentially disrupt the entire BitCoin economy by effectively "rewriting history".
I'm not sure this is a good thing. Every advancement seemed to have moved the needle to this direction. While everyone was able to run CPU miners is was very democratic. Then GPUs came, but still people could drop in a few hundred, and continue. After FGPA, and the ASICs, it's not just very large firms, where smaller people can only "rent" nodes, and hope they can trust the infrastructure.
We might need a "reset", where ASIC is no longer viable, but I'm not sure that would still be possible.