The new Microsoft Bing search engine is online now marked as "Preview". You can test drive it now yourself. Microsoft initially said to roll out Bing fully on June 3rd, but it is available for you to use now.
Bing focuses on Shopping and Travel and tries to help you make better decisions.
My initial impression is that the relevancy and freshness for normal web searches is just not good. Microsoft is not pushing the general search capability of Bing, but of course it is offered.
Bing also has News search, which doesn't seem to be up to the level of Google News. The user interface is nice though. I also like this roll-over page preview thingy on the right of search results.

Try Bing here.
We have featured some Bing Reviews last week.