I hope that they don't make one.
"What You Leave Behind" was perfect, IMHO. It tied up all the loose ends and left enough unanswered to leave it up to the viewer to decide.
Having Sisko return to DS9, Dukat being freed from the Fire Caves, Odo and Kira reuniting, etc., would just be anti-climatic.
A total CGI, with the actors coming back to voice their characters might be cool though, if it was set before WYLB, IMO.