I'd say it's going to be a 50/50 split again or 60/40 split for Dante. The reason why I think that is because Nero is supposed to eventually replace Dante. I'm pretty sure that's always been the plan: to introduce a new protagonist that everyone can get behind, for him to continue Sparda's legacy, and to basically be his second coming.
So I would assume they're going to try to make Nero more likable to the mainstream gamer audience, by making him more badass and less emotional (or possibly more emotional like DMC3 Dante). Maybe more like Vergil, considering he has always been a popular character, but they can't really bring Vergil back considering he's most likely dead. So they might incorporate Vergil into Nero, or simply try to make Nero his own character. It's going to take some time for people to warm up to him again, hence the 60/40 or 50/50 split.
I would find it very strange if Nero were just tossed aside, especially when DMC4 SE continued the Fortuna storyline (sort of). Besides, Nero was really not a bad character -- he felt sort of like DMC1 Dante combined with a little bit of DMC3 Dante and the overall seriousness of Vergil. They just need to make a more original plot, and one that they have full development time for (instead of just one year).
As for whether there'll be a DMC5 like tehrugger said... yes. I remember Kobayashi (I think) clearly saying they wanted to revisit the classic series. We don't know when - it's possible they just want to focus on making easy money with IPs and remasters they have confidence in right now. But it'll come eventually, and I hope Capcom will be more like the old Capcom then.