I was watching an AdWords webinar today on Optimization goals (you can view it on-demand); and Google had a screenshot showing what they consider the same or different keywords.

While upper versus lower case usage has never been used to differentiate keywords, diacritics has been questionable at times. Is saké the same as sake? The answer is yes, they are different words; and if you are using exact or phrase match – you should add them both.

Here’s a screenshot from the webinar showing a few examples of what the system reads: