There is still time to sign up to take part, but the deadline is coming up in a few hours at 2359 ZULU time today, 2021 March 28th, so hurry up if you want to get up and go.
Throughout this week I will be updating this post with more information, including my in-development flight plan, and linking to preparation streams where I haphazardly stumble through manuals, software, and flying aeronav geekery to prepare. Sorry! Here is a video tutorial about making a flight plan for MSFS2020 with Little Navmap (thank you, Howard)!
Good news for people in rural areas. Speeds of 100 Mbps down and 40 Mbps up are expected, and most of the planet is supposed to be covered by the end of 2021.
More information in this Reddit FAQ, including a link to this coverage map where you can click on a cell to open a window and then click on the little camera icon on the top-left to open a detailed map of the cell.