Soderbergh was attached to direct, but once George Clooney left the project, things began to go down hill. Soderbergh offered the lead role of Napoleon Solo to Matt Damon and Michael Fassbender who were both busy and then Bradley Cooper, who passed. Not too long ago Channing Tatum was also rumored for the role.
As for the other leading role, the studio wanted either Ryan Gosling, Joseph Gordon-Levitt or Alexander Skarsgard. However, Soderbergh wanted Joel Kinnaman, who unfortunately was also busy, which is when Joel Edgerton became rumoured for the role.
Apparently, Johnny Depp also read the script and became interested. He would have taken it as well if Lone Ranger had fallen through.
Really, it’s no surprise that with all these conflicts Soderbergh has left the project. Hopefully at some point in the future though things will work out and he’ll be able to get it off the ground.