Mobile Search advertising is heating up.   Sources say talks are underway for Microsoft’s Bing to replace Google as the default search engine on Apple’s iPhone.  What does this mean for Google?  The rivalry between once-partners, Google and Apple, has a heat of its own.  As Google continues to push its Android and Nexus One phones, competition increases for the iPhone and its current market domination.

According to AdMob, most mobile advertising impressions currently come from the iPhone and iPod touch.  Although Google has a steady, commanding hold on mobile search today, the tables could change with such a deal.

A Bing/iPhone partnership no doubt helps Bing to gain market share, exposure, and a positive brand image.  The search engine (whichever chosen) also receives revenue for ads placed.  If advertisers recognize Bing as a top mobile engine, perhaps the online PC market share could increase simultaneously.  While Bing has all of these factors to gain, Google is likely to prevail.  The launch of the Nexus One in particular will help Google to maintain its current market share on mobile search.  Even with such a deal, iPhone users could still go through the browser to google.com if preferred.

The potential alliance and growing rivalry clearly says mobile search continues to gain popularity.  It seems consumers are beginning to show mobile advertising will soon be in comparison to online PC search.  Advertisers beware, search on mobile is hot!

What’s next?  Will mobile advertising emerge as an industry of its own?  Many believe it will soon be time to watch who comes out on top with the battle between Google’s Nexus One and Apple’s iPhone.  If Nexus One proves as successful as Google hopes, the battle may only continue beyond search.