Ann154 is correct.  Bing is still the search application that comes up when you use the search button at the bottom of the phone.  But there are plenty of workarounds to get around Bing.  Personally, I use the Google search widget on my main home page  for searches, navigating, driving directions and messaging.  With the widget, I don't really care that the button calls up Bing.  I just don't use it...