This is part of why it takes much longer for mining rewards to be confirmed than other payments.
Since most people mine as part of pools these days, it probably doesn't matter too much. The average rate for the pool won't be affected too much (though I suppose pools which have been on the 0.8 block chain will hurt a little bit). There may be a one or two individuals who have mined a block and lose out by this, but if so, they were rolling the dice anyhow by mining outside of a pool; you can't expect a consistent income by mining over a span of 13 blocks.
Most pools pay out as soon as the block is mined, or at most one or two blocks later, and pay for any blocks that are later reorganized out of the chain from their own pockets. I fully expect to see several pools fail and take some or all of their miner's funds with them as a result of this incident.
Most pools don't distribute funds to their users until 120 confirmations have been reached so none of the coin that they mined will show up in their users' accounts. The only way this could cause problems is if the pool's maintainer is somehow still mining on the 0.8 branch which would not happen as the 0.7 branch blockchain has surpassed it in length.
If you are solo-mining and you found a block on the 0.8 branch of the fork, the standard client prevents spending newly minted coin with less than 120 confirmations. It will be the same as what happens when you get any other orphaned block, the funds will just disappear.
bzzt wrong. Most pools payout only after 100-120 blocks after the block they have mined is built upon by other miners (they go via an "estimate" then "unconfirmed" stage first). Additionally, the biggest mining pools either 1) only pay out their slave-miners after these confirms or 2) factor this in to their PPLNS slaves as a mining pool cost. Either way, you can bet they have enough in reserves to cover a small number of orphaned blocks. There will be no pools that fail after this event and I am prepared to bet on this.
Since most people mine as part of pools these days, it probably doesn't matter too much. The average rate for the pool won't be affected too much (though I suppose pools which have been on the 0.8 block chain will hurt a little bit). There may be a one or two individuals who have mined a block and lose out by this, but if so, they were rolling the dice anyhow by mining outside of a pool; you can't expect a consistent income by mining over a span of 13 blocks.