Recently, a client asked me about Google Mobile Search Results, and how the algorithm works to prioritize results aimed specifically at mobile users. In general, I believe that Google favors mobile optimized sites in their mobile search results. There are a number of usability features, such as location base services, screen real estate, and touch gestures that greatly enhance the functionality of Mobile sites. Google seems to be optimizing its mobile search results to deliver sites that deliver enhanced mobile functionality to the user.

For your reference, below are a few resources regarding Google’s treatment of mobile optimized sites.

Resources:

• Why Mobile Searchers Need Mobile-Optimized Sites from Search Engine Land
  

  Excerpt:
  “Mobility is a ranking factor for mobile search, and not optimizing a
  mobile site could make it more difficult to appear in competitive
  nonbranded searches where mobility is a factor. Likewise, having an
  optimized mobile site could make it easier to appear for competitive
  nonbranded keywords where mobility is a factor.”

  “As mobile search evolves and mobile ranking factors become more
  prevalent, brands that don’t optimize a mobile site today will be busy
  playing catch up tomorrow, building mobile links and paying attention
  to mobile ranking factors to their site. Search engines look at age of
  links and age of site when it comes to ranking because such factors
  are hard to manipulate. Success in mobile SEO will be difficult if
  postponed until absolutely necessary.”

• Official W3C Mobile Web Best Practices 1.0
• Mobile Usability from UseIt
• Transcript of Scott Huffman Presentation on Mobile Search at Google Searchology 2009