The interface itself isn't anything new. There was a site put up last year that does the same thing with Bing APIs. The magic was they (Google) were able to do it at scale, for all of their searchers. It's an impressive technical accomplishment for sure.
I always use Google. i never use bing in my whole life sometime if i am not getting a accurate result from Google than i use Yahoo. Google is far away from other search engines. it is very fast to showing results. it gives more ever accurate results.
Bing is for deal/rebate hungry ppl. Google is for rest of the people, or for those who don't even know Bings existence.
Comscore reported today that Google has increased its lead over Bing and Bing's market share dropped.