I remember a while back I saw a reply on DMC's facebook-page that was about a question regarding new story and levels for SE and the reply was that there is no new levels, but two cutscenes for Vergil and a hint/teaser on the future. So this might be the hint maybe? It's better than nothing I think. I'll see if I can find that reply again and post it here.
( At first I thought Lady's knees was a butt in the air behind Trish on the picture xD )
EDIT* Found what I were talking about, but it was a hint on the story, not on a sequel. But something to look forward to none the less. Here it is if you want to read it:
https://www.facebook.com/devilmaycr...0.1434897836./871467349585964/?type=3&theater
I'll post it here as well: "Action is definitely the focus here since it's a "special edition," not a completely separate title, but observant fans might catch a cool hint in there somewhere relating to the series' canon."