Apple is quietly disintermediating Google in mobile search. Tech writer Dan Frommer says that through its new, voice-controlled mobile “Assistant” feature in iOS 5, Apple could change the way people think of searching, building search-and-retrieve directly into the iOS user interface. And that it could potentially start to loosen Google’s grip on search.

He says Google has reason to worry. Apple replacing Google as the iPhone’s main web search engine, yet. However, Apple is teaching people how to search on their phones in an entirely different way — ideally, better – than how they’re used to searching today with Google in a browser. He

He says the what Apple is doing is big because, it is getting between you and Google in your mobile searches, by teaching you a new behavior. He writes:

Apple can then route those search queries and results however it wants — to Google, directly into iOS apps, to mobile websites, to Apple services, to iTunes, etc. Google doesn’t need to necessarily play a role. And that’s potentially dangerous to Google, which still gets the vast majority of its profits from search advertising.

It’s also another reason why Android is actually very important to Google — it represents Google’s opportunity to do the same thing, except making sure Google services are at the core of whatever user-interface features end up defining mobile search. So far, Google has been pretty successful with that. But in the U.S., Android isn’t likely to reach Google’s share of the desktop search market.