I'm not really the To Go Guy in this regards, but it seems to me that for various "distributed work generation" systems to work, pool's clients must be kept aware about all the transactions that need to go into the block OR ELSE.
There are 2 separate issues. Distributed verification of the block chain can be slow. A 1 hour delay before an error is detected is not that big a deal, only the latest transactions are affected.
However, if miners know that any illegal transaction in the block chain will be reversed within an hour, then they will make sure their blocks are ok.
Producing new blocks in a distributed way is harder. You have to produce and verify the block within a very short period of time.