Blue Eyes Riddle

I just came across this really interesting riddle that I thought I’d share here.

There is an island that is considered to be paradise. All the inhibitants of the island are Perfect Logicians, and every knows of every that they are Perfect Logicans.

Exactly 100 of these persons have blue eyes, 100 have brown eyes, and 1 has green eyes. The inhibitants do not know what his/her color eyes is. Everyone is constantly aware of everyone elses eye color but no person knows that there are 100 blue eyed, 100 brown eyed, and 1 green eyed person on the island.

If a person finds out his/her own eye color she/he must leave the island at midnight of the day she/he finds out! There are no mirrors or reflections of any kind on the island. Also, nobody on the island ever speaks except the Guru, who is the person with the green eyes, (she does not know her eye color and if she found out she would have to leave the island at midnight). The Guru says one sentence every fifty years. One day the Guru arrives and tells everyone on the island the following: “I SEE SOMEONE WITH BLUE EYES.”

Who (if anyone) leaves the island and when?

This is not a trick question, and the answer is a very logical one. It just needs a bit of thinking. Give it a try.
I’ll post the answer in a couple of days time.