Strictly, all blue eyed people need to hear the statement, right? If someone is missing and everyone (but them) knows the missing person has brown eyes, that doesn't change the logic of those who heard.
1. What happens if one blue-eyed person is somewhere else on the island when the foreigner makes his statement (and his absence is known to everyone)?
2. What happens if the next day a blue-eyed stranger wanders into the village, thereby establishing common knowledge that the day before there was in fact an additional blue-eyed person on the island (though no one in the village knew it at the time)?
3. What happens if the next day a blue-eyed baby is born in the village?
1. Suppose the foreigner makes his statement to a group of islanders C ("contaminated"), and the rest of the islanders P ("pure") do not hear it, and it is known to all that they didn't hear it. Call the group of blue-eyed people B. Then the intersection of C with B will kill themselves after a number of days equal to the size of that group.
2. Nothing. (I interpreted this as being without a statement by a foreigner.)
3. Nothing. (I also interpreted this one as being without a statement by a foreigner. With such a statement, it's the same problem as case 1; everyone will recognize that the baby, having not existed on Foreigner Day, can't know about nor have been mentioned in the statement.)
EDIT:
I should point out that I've assumed the foreigner's statement refers to the group he's addressing, not to the population of the island. ("At least one of you who I see before me has blue eyes".)
With a better interpretation of your problem 2:
2a. On some day, the foreigner addresses a village, saying "at least one person on the island has blue eyes". A blue-eyed stranger wanders into the village shortly after he leaves, allowing the villagers to believe that he was referring to the stranger.
In this case, there is no synchronization point, and "nothing" will still occur.
2b. A blue-eyed stranger wanders into the village the day after the foreigner leaves, allowing the villagers to believe that he was referring to the stranger.
As far as I can see, this has gone back to case 1 again. The foreigner's statement provoked a first day of blue-counting, and while it is revealed to have possibly not meant what they thought it meant, day 1 of blue-counting is sufficient for day 2. The blue-eyed villagers should kill themselves after a number of days equal to the size of their group. (The stranger, even if he settles into the village, will be unaffected.)
