Hence ASIC miner can never own greater than 50% network, (Hence Share price could hit a barrier, theoretically ) hell i don't think they'll want to approach 40%. Fearing BTC devaluation.
Look at BTC guild, as pool rate reached 40 % they took measures to prevent further increase,
The 51% Mitigation Plan
PPS fee will be raised from 5% to 7.5% on all new accounts. Old accounts will also be increased (PPS ONLY) to 7.5% after a difficulty change. If the pool eventually drops back under 40% for more than 72 hours, these fees will be turned back down to 5% after the next difficulty change.
More than 45% of the Network [last 2016 blocks]
Getwork based pools will be completely removed within 24 hours. All users on getwork have been warned in the past that it is a unsupported and not advised method of connecting. This should remove ~15% of BTC Guild's hash rate immediately.
More than 40% of the Network again [last 2016 blocks]
PPLNS fee will be raised from 3% to 4% after a 72 hour warning. This fee will be reduced back to 3% once the pool drops back under 40% for more than 72 hours.
The fixed price auction (First come First serve)>> maybe next, they'll donate a few blades to the poor, as broke as shit Indian subforum guy named rezuruct