I just can't see it. The always improvising, nervous attorney who fumbles his way through every case until the very end is now a jaded chessmaster with a smirk. They can't bring him back to his roots now and playing as Edgeworth 2.0 makes no sense nor fun at all, considering he's got his own gig now.
I just don't know, GS5 will obviously be about Phoenix taking back his attorney badge, but I just can't see that plot work, even if it means we'll get older Maya and Pearl. And Apollo is such an unappealing character that I don't want to see him as the main dude again.