I suppose it's not technically a fork if the majority of miners chose something is it? Here is a relevant quote from the development forum
Why don't we just let miners to decide the optimal block size?
If a miner is generating an 1-GB block and it is just too big for other miners, other miners may simply drop it. It will just stop anyone from generating 1-GB blocks because that will become orphans anyway. An equilibrium will be reached and the block space is still scarce.
I think this is exactly the right thing to do.
There is still the question of what the default behavior should be. Here is a proposal:
Ignore blocks that take your node longer than N seconds to verify.
I'd propose that N be: 60 seconds if you are catching up with the blockchain. 5 seconds if you are all caught-up. But allow miners/merchants/users to easily change those defaults.
Rationale: we should use time-to-verify as the metric, because everything revolves around the 10-minutes-per-block constant.
Time-to-verify has the nice property of scaling as hardware gets more powerful. Miners will want to create blocks that take a reasonable amount of time to propagate through the network and verify, and will have to weigh "add more transactions to blocks" versus "if I add too many, my block will be ignored by more than half the network."
Time-to-verify also has the nice property of incentivizing miners to broadcast transactions instead of 'hoarding' them, because transactions that are broadcast before they are in a block make the block faster to verify (because of the signature cache). That is good for lots of reasons (early detection of potential double-spends and spreading out the verification work over time so there isn't a blizzard of CPU work that needs to be done every time a block is found, for example).
So the gist of it is......... if we don't raise the block size limit we will have to make bitcoin clearing houses or the network will become unusable except for moving large amounts of money. And transaction fees will be 20+ dollars for moving money. Sounds like a bad idea to me. Exchanges are already the weakest link of bitcoin because government intervention is the greatest potential problem and taking down an exchange is the easiest target. Clearing houses would make things easier to disrupt. Destroy? Maybe not. But it will certainly destroy peoples wealth if they store it in bitcoins. The whole idea that raising the limit will create centralization of miners seems bogus to me and not an actual real problem.