I believe MSN has begun to follow the example of Google by returning Wikipedia results #1 for certain informational searches. A certain very general keyword I have been tracking (and was myself #1 for some time) has been fluctuating for a few days now, and I now see Wikipedia in the first place for that search where previously it had not been in any noticeable position. I tried this on a few other searches and came to this conclusion. Try searching for almost any country and in the top 5, if not top 2 are (almost) always the CIA World Factbook and Wikipedia. I haven't seen Wikipedia appear to this extent before.