Everybody who has worked with Microsoft Business Intelligence and haven't been living on a deserted island knows about Donald Farmer, who's personified Microsoft BI. Reading that he is leaving Microsoft is of course shocking news for us in the MS BI communities. However I believe he has good personal reasons and wish him the best of luck in his new job!
So what does this mean? I think Rob Collie has made a good analysis. Donald Farmer has been the face of the product line, but he isn't the product line. There are thousands of clever people at Microsoft that have been doing a great work in the background and that will continue doing a great work. Microsoft will continue to sell their BI products with or without Donald. On the other hand, QlikTech will benefit much from PR and credibility as well as getting a really clever guy like Donald Farmer. Since the BI market is very far from a zero sum game, Microsoft will not loose much but QlikTech will gain much more. Simple business logic!