I have always used
Google (or sites Google bought).
The folks that I know
that did use Yahoo
have all shifted to Google.
Don't know what's trendy.
Well I use google for most of my searches, yahoo for everything else. I tell you one thing though www.live.com is actually a very good and intuitive search engine by micro$oft, I have found myself using it more and more because I am not wading through five pages because of google bombing for hits on googles site.