bitchyFrom an end-user perspective, Microsoft would, based on past experiences, assimilate Yahoo's features and make them harder to find and cumbersome to use. (And require a "Passport" -- with all that implies.)
From an armchair economist perspective, I'm getting tired of seeing mergers where two companies combine to form one company that promptly ends up being valued about the same as it was pre-merger. Microsoft bear hug, Yahoo *squish*. No matter what premium they pay.
I agree with some of the analysts in the papers who have implied that the real significance of this is that Microsoft contains a current or incipient empty space that's Yahoo-sized.
EDIT: forgot to include the humorous link that was the reason I felt like posting this in the first place: http://daringfireball.net/2008/02/yahoo_translation
