The developers said a while ago they were planning this for an update, so it's fantastic to see them actually deliver on it. A shame it couldn't be released with it.
The developers sure are looking forward to it:
@gamingonlinux We're really excited to unite our players!— Worms™ (@WormsTeam17) November 21, 2016
The beta will start on Friday 25th of November at 10AM UTC and end on Tuesday 29th at 10AM UTC. You only need to opt-in to the "beta" branch on Friday to be able to test.
Looks like it could be a good contender to show off in our livestream on Friday, if anyone fancies joining in?
Have many of you played it, if so let us know what you think in the comments.