Google is the default search engine of most Microsoft users. There's no way the iPhone is going to lose Google search. Meanwhile, search is simply not a huge part of my iPhone experience.
Maps is actually a bigger deal to me --- but maps is also easier to replace.
Google is spending upwards of a billion US dollars to make Street View, in the process creating a top-notch street map of the World. And now they provide that data free, I doubt Google maps is so easily replaced, even with Bing Maps.
Maps is actually a bigger deal to me --- but maps is also easier to replace.