As you’ve probably heard, the 2020 APS March Meeting was cancelled due to concerns over coronavirus. It was cancelled only 36 hours before it was scheduled to begin. Myself and many other scientists were already in Denver when we heard.
I am, of course, very disappointed to miss this chance to meet up with my fellow physicists, but I believe APS made the right call. Since then the outbreak in the US has substantially worsened, and a gathering of 10,000 people from all over the world (including at least 500 attendees from just-upgraded-to-level-three countries) could have made things much worse. APS has handled this very well. They have already started refunding the registration fees and they’ve even been in contact with US funding agencies to make sure that attendees can still be reimbursed.
To my delight, my community really made the best of a bad situation. Many of us were already in town, so there were a number of informal meetups. I was able to present my talk at mini march meeting sessions at MSU–Denver and CU–Denver.

The Micro March Meeting at MSU Denver March 3, 2020
Beyond that, many of the talks are being posted online at virtualmarchmeeting.com including talks from the FECS invited session I helped plan and my own talk. I’ll be posting separately about those sessions soon.
All of this self-organized coordination between attendees was facilitated by APS’s new internal message board: Engage. I’ve been testing the Engage platform with FECS and I was uncertain how it would work when scaled up to a huge userbase. My concerns were unfounded: it worked great! Normally there would have been no ways to attendees to communicate with other attendees they didn’t already know, but Engage made it possible to organize meetups for those (like me) who were stuck in Denver.
Update (2020-04-01): More information about sharing your March Meeting talk here.