There was a lot of talks yesterday at Pubcon Austin about how Google was changing up its algorithm today to give preference to mobile-friendly sites.
So sites that are not mobile friendly are expected to get diminished exposure in Google, hence Mobilegeddon.
Google has a mobile-friendly test you can run for your site and advice for making your site easier to access from mobile devices.
You want to see a result like this…
If you fail the test, changing your site to make it mobile-friendly is not too late.
If you are using WordPress, there are many responsive themes, meaning they will automatically adapt to mobile devices.
I use the Genesis Framework by StudioPress, and I highly recommend their many responsive theme options.
Good luck weathering Mobilegeddon.