In an interview with Sam Raimi, Bloody Disgusting correspondent Superheidi got a nice scoop on the developement of the Evil Dead franchise.
In regards to 'Evil Dead 4 Raimi says, "There will be an Evil Dead 4, and there will ALSO be an Evil Dead Remake. The remake will be produced by Ghost House pictures, (his company with Tapert) and it will star a new cast and a completely new director. The point of Ghost House is that we want to bring new directors (like Takashi Shimizu of "the Grudge" to Hollywood and give them a chnace to make a good horror film."
Raimi will be directing and producing Evil Dead 4, which will star Bruce Campbell as ASH and will also have many of the actors from the previous Evil Dead movies.
Raimi added that "This is the project I really want to make. The remake can belong to someone else, but part 4 will be a continuation of the original".