With Robin van Persie going to Manchester United, the lineup will be much different.
According to Arsenal's official website, the Gunners have agreed to send their star striker to United, making the Red Devils a favorite to win the league. Van Persie will change their roster slightly, but more importantly, he will improve the effectiveness of their attack.
Even if United can stay healthy, Sir Alex Ferguson will tweak his lineup on a regular basis. However, this is likely how the team will look once the van Persie deal is finalized.