Screen Rant reports Firefly may have found new life as an animated series, set in the period between the TV series and the film Serenity. It supposedly will feature the same characters as the TV series. Perhaps the original cast will do the voices, SR isn't clear about this.
SR indicates the new project was first broached a couple of months ago. Joss Whedon will not be involved in the new effort, although he is said to be supportive.
I agree with the commenters that animation is less good than live action, but 'tis better than nothing.