I think we won't see another Indiana Jones film, as this one did poorly at the box office. I feel the last major Indiana Jones product with high production values will be the videogame by Xbox gamestudios (Machine games, who made the latest Wolfenstein titles).
But who knows, maybe there will eventually be an adventure film revival, but by that time it won't have any of the current stars/people related to the franchise. x
Anyways, while I don't think Dial is that good, it is a fitting ending and I am glad they made it and have Crystal Skull not be the end. Crystal Skull is like half a good film, but then just sucks for the rest of the run time. Dial is middling throughout with a couple of highlights and a nice ending.