About 4 years ago Genndy Tartakovsky mentioned he was working on Samurai Jack: Movie, however, due to the flop of the The Powerpuff Girls Movie the film was canceled. In 2012 it was re-announced that Genndy was working on it again and it was in per-production with J.J Abrams.
Considering that Samurai Jack is owned Cartoon Network Studios it seems some deal was worked out between Genndy and the network. I guess Genndy was not totally burned what SBT got canceled.
The film currently has $20 million in financing and will combine traditional 2D animation with stereoscopic 3D. He is also working with Digital Production at Sony Pictures Entertainment.