This was the round up: No, bitcoin isnt about to be taken over by a massive cartel.

After Ghash.io’s large stake came to light on bitcoin discussion boards, members of the pool started flocking away, reducing the pool’s share of mining to 38% over the course of just seven hours. This is just more and stronger proof that the system is self-correcting—such mining pool exoduses have happened in the past.

Now it's around 36% as you can see here: https://blockchain.info/pools

This is the discussion thread: https://bitcointalk.org/index.php?topic=407843.0