There is concern among bitcoiners, that pool with >50% power can exploit the network with double spending transactions. I think that someone should make a service for monitoring blockchain forks and double spending attempts. I'm pledging 50 BTC for such service; if you are concerned with this problem too, add up your pledge.
To receive award this service should provide at least
1) Real time list of blocks, including orphaned ones
2) Real time list of transactions with double spend attempts
The whole point is not to have a centralized authority and this sounds like it is creating one. Doing so will destroy the very nature of bitcoin. Instead, pools and miners need to do what they have to to make the scenario impossible [assuming Slush comes up to full capacity, work needs to be done such that at LEAST no two pools add up to much more than 50% of the computational power of the network]. If pool operators and miners don't have the will power to do this, then bitcoin is at risk.