If we're lucky with injuries and a mystery cancellation of the African Cup of Nations, yeah.
But seriously, there's no reason that the current squad can't retain the title. We have a team of talented (in a few key places, absolute World Class [Hart, Kompany, Yaya, Silva, Aguero) players who have now been playing together for a while, we have the best strike force in the league (and I'd argue in Europe, except for Barca) and a manager who knows how to retain a title.
But we'll have a much better chance if we bring in 2 or 3 players for the parts of the team that we do lack in. We need a 3rd experienced CB and a deep lying playmaker. We could also do with a dedicated winger.