With regard to growing Asicminer's total hash rate to more than the current 20s%...
An attacker who controls 30% of the network has a 20% chance of solving 6 blocks in a row...so even though we are not the dreaded 51% attacker, the network would still be exposed to some risk by friedcat having 30%.
Moreover - if friedcat does get 30%, imagine that competitor pools of total size 40% gets taken out (eg ddos). Now Asicminer's 30% suddenly becomes 50% of the total, and again we are the attacker.
that's why what I was saying the hashing needs to be monitored. if you only 2.4 blocks of each 6 blocks (or 4 out of 10 in you like base 10) mined you will always be 40% of the network. ..if the network slows down you shut down some hash. nobody cares about a luck streak. . .they care about sustained hashing power. remember % of hash (and total network hash) are calculated by speed the blocks are being solved over time is what matters for network perception, not your potential to hash rate. So if there is a software governor controlling the hardware and we never allow more than a 4 of 10 you will never be more than 40% of the network. you don't have to worry about sudden drops in network hash or any of that, because the governor will never allow it.