I kinda of see what you mean, people wouldn't have a choice to act the same as they currently do, they wouldn't be able to lie. Everyone would be forced to change personality, however, not everyone would be willing to do so and things would go bad...
There would definitely be complete chaos to start with, but I think we'd come out of it better than ever before. There would hopefully be better ways to implement it than to just throw it into society as it is right now and just hope for the best.
No I really don't think it would be a good thing. Like I said, a person's mind is his own. Unifying it with others would be the definition of taking it away, because then you wouldn't have it anymore.
The more I think about this the more frightening it sounds, I wouldn't want to be forced to take in the thoughts of someone who is insane for example. This idea might work in some sort of place where everyone is good, it sure wouldn't work on Earth, where the vast majority of people are stupid, greedy, and brainwashed.
You would take in the thoughts of someone who is insane and be able to rationalize them with everyone else's sane thoughts. And the insane person would most likely be able to correct his own thoughts whenever he can't justify his paranoia anymore.
And no one would be stupid, greedy, or brainwashed if everyone's mind was opened up. You wouldn't be losing your mind, it would be just as much there as it is right now, it would just be joined with everyone else's, and then improved upon.
Our brains have a built-in auto-correct system. It would be bad at first, but we would adjust into a more uniformed state of consciousness where, when all of our minds are unified, we have to work together. It would be the manifestation of "one for all and all for one."