Hollywood Reporter have annouced the right for Casshern in America have been signed over to Dreamworks. OK, so now we know there will be a DVD release sometime down the line, but expect to wait around a year (possibly) because they will probably do a cinema run first. Even then you can't be sure you will get a disc as good as the Japanese edition which has just come out.
The official Casshern site has been redesigned slightly so you can now see a really nice photo of the DVD packaging, if you desire, here