Here is a good explanation of it:
Basically, cooling the beer creates the haze by bringing out the proteins that were not taken care of by quick cooling the wort. Try warming one up to see if the haze goes away. That means the proteins are dissolving back into the liquid.
As stated above, and in Palmer's book, it is aesthetic only, and will not interfere in the taste or drinkability.
Bear in mind, though, that I am a complete neophyte with brewing, as I am fermenting my first batch now, but I believe I am correct on this.