This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results.
Google also specifically stated at the SMX conference that this will not impact desktop searches.
This is targeting just mobile searches. Of course this may change in the future. It is also possible that there there might be some indirect impact on your desktop rankings. Google seems to have incorporated usage signals into the rankings. If your site is mobile friendly and gets a ranking boost it could lead to more traffic which leads to more usage signals which eventually could lead to a desktop search rankings boost.
