It will hugely depend on the WC and his form in November.
Journalists vote in the France football ballon d'or award, while the national coaches and captains vote for the world player of the year.
Usually people remember what happened recently and what happened at big competitions like the WC or the CL, SO if Argentina doesn't have a good WC and if Messi drops in form come November the way he did in September/early October 2009, then he won't win anything at all.
Ballon D'or is something thats driven by WC results once in every four years - journos prefer to do that way in WC seasons. Blatters FIFA award, Messi should win easily, irrespective f whatever he does in the WC.
Cannot see any outstanding player from Inter being in line for Ballon D'or even if they win the CL.
As for Messi, cannot figure out the reason he gets stoned on his international form. So far he was the player of the tournament in the two he has featured after the WC 2006 - Copa America and Olympics.
Also his form was good if not brilliant at the international level before Maradona took over.