Vergil will be back. Capcom won't give a **** If its game designers/creators don't like him. It's a huge fanbase out there, which needs him back. He was left unexplored and has potential. All the ones who disagree, either dislike Vergil, or are too shortsighted to seize the fact that It could be a nice twist to the storyline.
Devil May Cry could revive and energize itself. They tried It with Nero, but people kept wondering who the **** Nero was. They didn't even give the kid enough innovative and fresh moves. Instead they got repetitive and boring after a while. If It wasn't for Dante's addition as a playable character in the main storyline, DMC4 would have been a worser game than It already is.