More options could be implemented for AdSense publishers, allowing them to specify keywords of their own. While Google has been reluctant of this there’s no indication that this will not happen in the future.
Also, a lot of people are demanding a clear specification of the pricing policy of AdSense. Google has given no indication of why this isn’t public information but at this moment it seems highly unlikely that such information will ever be present on Google AdSense.
Another feature that could find itself into AdSense would be letting website publishers see which links are generating clicks on their website and based on what keywords they arrive there.
This could end up being a major issue that could threaten the entire system as it could perhaps encourage more adsense only websites as profits become more transparent. A lot of people may make AdSense-only sites, designed just for making profits through AdSense.