Devil May Cry 4 left us with many more questions and didn't really answer anything from any of the past games' plotholes. So in a sense, Capcom exhausted the original series, imo. If Devil May Cry 4 had a completely other storyplot which explained some of the things from the past 3 games, such as what happened with Vergil between his disappearance in DMC3 and his sudden change into Nelo Angelo in DMC1, and maybe what happened with Dante after he drove to Hell after DMC2, stuff like that.
The current Devil May Cry 4 started on a new story without finishing the one they had already started and now Capcom started a third story with the new Devil May Cry. Capcom could learn much by looking up the word "closure". It's odd why they have so many troubles doing that with Devil May Cry when they did a terrific job with Megaman Zero series. I mean, after four games, the whole story in Megaman Zero was told and had closure.