If the defensive awards don't separate PG and SG, I think he may have a shot at it with more consistent minutes and a larger role next year. This year, his play has been too inconsistent.
If he IS going for the award as a SG though, I don't think he belongs in the conversation. Against SGs, I don't think he's a top level defender. His height + lack of strength gives his opponents as much of an advantage as his quickness and tenacity takes away. We've already seen Henderson, Hayward, and other bigger players take advantage of their size against him.
I can't see AB ever matching TA (or wade, Kobe, lebron, or sefaloshas) defensive prowess against SGs.