All that the BTU coin folks require is 51%. After all, they are entirely convinced that having 51% hash rate equals to being Bitcoin, which is on a level of absurdity not seen in a long time. Do you think that it is not possible for them to reach this number?
Then they will do a genuine hard fork and two coins. But in order to REALLY do so, that means, when they will start producing *incompatible blocks* and mine on one another, they have to realize that they will make an altcoin, losing bitcoin's first mover value proposition, which is essentially the only thing that keeps it number one for the moment. So I wonder whether they will really do that. In any case, if they do, there will be two bitcoin chains, two coins.
ETH/ETC all over.
I think it would be a "good thing", because then the market can choose. But I wonder whether they will dare to do so.
Bitcoin's first mover advantage is still too valuable in my opinion. It would be great if bitcoin could hard fork into two coins. But I don't think it will.
They might, by total ignorance of the system, thinking that 51% is imposing its will. But with a hard fork, that is NOT the case, as the two chains are incompatible. Non-BU miners will reject their "longest chain" as simply invalid, and build on the valid chain with smaller blocks. That's how the two prongs of the fork will separate. I have a hard time thinking that this would happen by ignorance.