Well lets start with the obvious:
I would also suggest that they have included:
Overture as Search Engines.
Also don't forget
But then I got stuck at 9, so I then did a quick Google and came across a page that listed more than 12. Although it claims to be "updated" I am not sure when this was.
The link is (hopefully it is okay to have this link here):
Not sure I agree with some of these.
I also found [hitwise.com.au...] which provides a graphical view which was update June 2004.