I disagree with the conclusion on the page. I think they'd all (save the Guru) leave that night. If indeed they're all perfect logicians, they would recognize that the Guru isn't like any of them (as the Guru can speak/communicate). As they can all see everyone at the same time, they'd be able to recognize that with the exception of the Guru, everyone's eye color is either Blue or Brown. In considering that there are 100 people with Blue eyes and 99 others with Brown (or vice versa), they'd all be able to logically deduce that they had the same eye color as 99 people on the island, but not the other 100. The Guru, on the other hand, is about to get pretty lonely.
I guess if they took out the idea that if something could logically be deduced that it would be known immediately out of the equation this wouldn't fly, but as arakimos said, arbitrary restrictions, etc.