In somewhat predictable news, the PS4 won't be backwards-compatible with existing DualShock controllers - though it will support the Move just fine.
Despite the DualShock 3 using the same Bluetooth 2.0 connection as the Move, Sony are adamant that hardware backwards-compatibility will not be possible. "No," Shuhei Yoshida told Polygon, "[the PlayStation 4] doesn't support DualShock 3 but it does support PS Move."
Sony was also unwilling to discuss whether current-gen Bluetooth headsets and other peripherals will also be supported.
Annoying? Yes. But to be fair, the DualShock 4 packs plenty of new features that Sony will want to integrate into the core PlayStation experience - not limited to PS Eye motion control and touchpad functionality. Not to mention the whole sharing thing (though technically the DS3 would have enough buttons for a dedicated 'share' button, since Start and Select have both been rolled into 'Options').