According to one thread though, China is currently controlling 80% of the hashrate. Would that become a worry if they decide to join together?
Do you think a 51% will happen at all?
A worst case scenario would be the forced takeover of mining farms by the Chinese state. Of course if such a thing were to occur then the price of BTC would plummet (so such a move would be politically rather than economically driven).
It is hard to see any way around Chinese domination in one way or another as the vast majority of computing devices in the world are manufactured in China (and western corporations can only blame their own greed for creating this situation in the first place).
Even if you had a coin that could be mined with smart phones (i.e. requiring very little electricity) in all likelihood China would control the majority of such nodes as well (as nearly every Chinese that I see on a daily basis has a smart phone - and I mean even cleaners and construction workers).
In some ways perhaps it could make sense that more localised block-chains might serve a useful purpose (although one of Bitcoin's biggest selling points is it being global and not under the whim of any government).
Also in places such as Iceland where electricity is virtually free and temperatures are low enough to require little (or maybe even no) cooling there will always be a potential for growth so we might find that hashing power ends up concentrated in such locations over time (I guess then it is a matter of how many such locations there are and in how many different countries).