>The biggest change to the foundations of Android to date: a modular architecture that makes it easier and faster for hardware makers to deliver Android updates.
With any luck, this will end the huge security/update problem Android has. Right now an update is dependent on the chip manufacturer's drivers, then the OEM adding them to the ROM with their custom "improvements", and finally the carrier pushing the update to devices. Right now it just takes one break in the link and a device goes without updates, which is a security disaster. If Google can push updates from the Play Store (presumably the end goal of Treble), none of this will be a problem.