I also tend to use Google for everything. I tried Bing but was unimpressed and noticed no major difference between it and LiveSearch. As for Yahoo I used to use it back in the early days of search providers but after using Google I never looked back. However, I do wish that someone would do what MS was aiming for with Bing only this time actually introduce us to something new and improved.
I continue to use Yahoo as my primary search engine although I am becoming increasingly dissatisfied with everything about Yahoo. I loathe "Giggle" and do not trust them (with my personal information OR browsing history) and simply would not use a search function if they were the only one left. I intend to check out Bing to replace the increasingly troublesome and aloof Yahoo.