Today I have seen NEW look of Yahoo! search. It is called Yahoo! Search Assist. Right now I can see this feature in Internet Explorer only not in FireFox.
This Search Assist is more user friendly than old one. It helps users to match a word when you typing. At the same time when you write known general term it provides suggestions that include complete searches. Here you can find more about Search Assist.
I would say it is a good tool for users. I love it, and hope you also like.