I would like
1) the option to play with more power and strength in midfield
2) cover / alternative to Song, who has had absolutely no cover for several seasons now.
2) someone sober to throw an arm over Song's shoulder and tell him he's not Liam Brady. He should focus on getting the ball and giving it to an outlet. Of course, it would help if he had real outlets available. This is why it would help for Wenger to add (e.g.) Kagawa to Podolski, and for Wilshere to get well soon.
In summary, bring in M'Vila and knock some sense into Song. Be able to pick a 3-man midfield from Song, M'Vila, Wilshere, Arteta on most weekends.