Keeping RVP and Walcott, the signing of Podolski and us signing Giroud - for Arsenal to really challenge for the title
We would need to be lucky not to suffer medium to long term injuries to Sagna, Arteta, Wilshere, Song, Sneezey, Kos, TV and Mertesacker.
We would also need real improvement from at least two of AOC, Gervinho, Ramsey, Coquelin.
Defensive structure throughout the team to improve our defensive record by about 15 goals.
In other words - we would need massive luck, along with better than expected performances from quite a few players.