The Ethereum community has elected to do a hard fork as a way to resolve the chaotic DAO exploit. Around the 20th or 21st of July (depending on where you live), the hard fork will occur when the MainNet block reaches 1920000 (the fork trigger).
Most exchanges have declared that they will stop taking Ether deposits before the fork trigger. deposits shall resume when a clear winning single chain is identified. As o this point, they will only support that chain. The time when deposits will be stopped is clear, but the amount of time needed until the deposit thaw takes place depends on how the process evolves. If it goes on smoothly it should be relatively short, maybe not even taking more than one or two days, however, in spite of the problems caused by The DAO it is yet uncharted territory and stakeholders such as exchanges are being very cautious in handling the situation, at the end of the day they have a "fiduciary" duty in the way in which they hold funds on behalf of a third party.
The reason for the above is that if a deposit is made whilst there's not a clear winning chain such deposit addresses are subject to a replay attack.
Taking into account how the code was written, a transaction sent on one side of the fork will only be sent to peers on that side of the fork (p2p network split) but the transaction on the other chain would not be invalidated, thus the transaction would be valid on both chains if you were to re-route the transaction through a node on the other chain. This fact would create lots of potential attack vectors, with a high probability of ensuing mayhem and the need to roll back the chain to the post-fork pre-replay-attack fork, which would basically imply the collapse of the system in the way in which users wouldn't be able to appraise what te situation is, and probably without clear guidance on how to proceed.
In light of the above, a number of basic questions come to my mind;
How long will it take?
What will happen with open margin positions in exchanges?
Is the DAO subject to replay-attacks too?
What happens to ether cloud mining deposits?
What happens to Ether mining during the process?
How to control what fork your cloud miner votes for? (I haven't seen anybody asking this in any of the cloud mining services in spite of having directly asked Genesis mining without receiving a response for this)
... and a large number of other questions I can't think of right now but which surely linger in some obscure "code corner" or in your mind.
The truth is that, even though I'm a great fan, investor and advocate for Ethereum and smart contracts, this situation is highlighting; a) the immaturity of the technology, and b) the maturity of the bulk of the Ethereum community.
Anyhow, what happens in the next couple of days will determine the fate of Ethereum and the $1bn that gravitate around it... Off to get some pop corn!
What's your view on this?