The real danger is pool operator corruption not a single pool getting >50% hashing power.
Take gigahash and some other leading mining pool. Combine their hashing power and Bitcoin is done. DEAD. All hail to peercoin, you should start buying peercoins already (
http://imgur.com/a/dG66c) as this coin is much more resistant to 51% attacks.
Someone controls the pool, right? That someone has a family to be tortured in order to bring down Bitcoin. If money won't corrupt the pool operator, there are other things that can be done.
Those who know history, might even look back to Molotov–Ribbentrop Pact which may very well happen in the context of leading pool operators.
1. Develop a 51% attack proof altcoin.
2. Bring down Bitcoin with the analogue of the Molotov–Ribbentrop Pact amongst pool operators.
3. Everyone switches to 51% attack proof coin.
4. Profit
I diversified to peercoin long time ago and been stake-mining for a year now.
