Sci Fi has found lead actors for "Riverworld" and "The Phantom," its upcoming movie events that will serve as trials for possible new series.
"Battlestar Galactica" veteran Tahmoh Penikett and "Smallville" supergirl Laura Vandervoort will star in "Riverworld," and Ryan Carnes ("Desperate Housewives") has been cast as the Phantom.
Penikett is best known for playing Helo on "Battlestar." In "Riverworld," he will play war correspondent Matt Ellman, who is killed along with his fiancee (Vandervoort) but awakens in a mysterious world populated by everyone who has lived on Earth.
Source:
http://www.hollywoodreporter.com/hr/content_display/news/e3i701e5f503331aba04a5ed840f1b14291
I assume that the new Riverworld will be based on the series of novels by Philip Jose Farmer which have the same plot.
I believe there was another Riverworld pilot made a few years ago but it never followed up by a series.