Google has been saying that website owners need to get their mobile game plan together. My suspicion is that they are tired of seeing all the bounces from non mobile websites when people search on their phone. Personally I have stopped using Google as much on my mobile phone especially for local searches. Yelp for better or worse is my goto resource for getting local information on my phone because I know I will be able to read Yelps pages easily. On google it is a crap shoot.
But just having a mobile website is not entirely enough. You also need to deliver a relevant experience to your users. Yesterday Google came out with specific details where it will be penalizing websites that don’t deliver what users expect when searching in google. For example if the Google result is for a specific page on your site but when a mobile user clicks on the link they get delivered to the home page of your mobile website. I have first hand experience of this and it is frustrating and always causes me to hit the back button.
The simple answer to a lot of mobile seo it to convert your website to a responsive layout. This allows you to keep your existing URL structure and deliver the same website to all devices but it will adopt the layout to the screen size you are currently using. There are a number of things you can do in addition to this but making this change will have the most dramatic effect while minimizing your effort.