For those who prefer Google over Bing, MetroG is a Windows Phone app may be an app worth giving a try. MetroG is a search app for your Windows Phone that reaches out through Google to search the web for all your keywords.
MetroG is a nice looking app with a conservative appearance. The main page has your keyword search field up top and three button search options (news, web and images) down below. On paper, MetroG isn't a bad search application but its performance seemed to fall a little short.