They may add more ads, and bigger ones, but that does not mean they have as many people seeing them.
Probably the only ones seeing those ads are those employed by microsoft, because google is blocked by their server (or something)....
I don't mind monopoly, if you look at the way Google is running it...
It's free, the searches are pretty right on, the ads are hidden, and not disturbing, and the pages are clean and small of html code.
In contrast, Bing is pretty unclean in code, they have plenty of distracting background pics and toolbars and so on...