Microsoft officially announced Bing on Thursday. Several sites published reviews of the new Bing search aka decision engine. The overall verdict is mostly that Bing is a nice step forward for Microsoft, but not a Google alternative.
The Bing interface is neat and in many cases helps to quicker find what you are looking for or gives you more aspects of the results. For product comparison and shopping Bing is a good new tool to use.
Search Engine Land has a nice search result comparison between Bing and Google that shows how different the two are. In this report Search Engine Land explains the new features of Bing.

More Bing Reviews:
Arstechnica
TechCrunch
CNET
PC Mag

See also the Bing site. Officially Bing will launch on June 3rd, but it supposed to be a soft roll-out until then.