It’s very early days into Google’s mobile update. There have been some rumblings online about ranking drops, but not many. The important things to note:
• The full roll-out will take a few weeks, so ranking drops will appear over time
• There isn’t enough data yet to make many meaningful decisions
• Desktop rankings will not be affected
• The update is applied to pages, not entire sites
• Google has a mobile-friendly test: https://www.google.com/webmasters/tools/mobile-friendly/
The bottom line is that if you don’t have a mobile-friendly site, this update should be one more encouragement to get one, but should you panic? At this point, we don’t have enough data to know.