Considering he had possibly his best games for us at the end of last season, surely it's worth keeping him.
We can't sell arguably two of our better midfielders, Sanchez and Chamberlain in the same window, as well as not having Cazorla for most of the season.
It would leave us with Ozil, Ramsey, Walcott and Iwobi which is considerably poorer than we had last season.
If Conte, Klopp and Guardiola have all showed an interest in him, and Wenger himself obviously rates him, then why sell him.
He is not like Walcott or Ramsey, who are about as good as they are going to get.
He is still young enough to become a better player.
If he stays, I could see him having a very good season with us.