Great video! Thanks. I agree with what you are saying.

The next time someone shows a chart with a pool at 50% it would be interesting to see what the 7 day chart shows. As you say, if ghash did something untoward, the backlash from their 180,000+ miners would cost them more than they could ever gain from it.

My biggest concern is corporate miners. As they grow in size and number they may not have bitcoin's best interests at the top of their list, and collusion is not below their standards if there is a buck in it. Any public backlash would have little effect on their operations, beyond a flood of phone calls, twitters, and emails that they would ignore. At this point in time they aren't a threat... but keep a close watch in the future. I feel, if there ever is a real threat, that is where it will come from.

So long as small miners keep up with their hashing power and mine on public pools we should be safe.