It’s limited support, but at least it’s there.
One of Sony’s promises for the DualShock 4, when it was first unveiled, was its compatibility not just with its native console, but also with all manner of other devices as well- including PCs (with which it has been compatible for a while now), microconsoles such as PlayStation (Vita) TV, and the PS3 as well.
That last part of the puzzle became concrete reality today, as the astute folks on Reddit are now reporting that it is possible to use the DualShock 4 controller with the PlayStation 3 now- provided the connection is wireless.
The connection needs to be made over Bluetooth (and does require a wired connection for the initial setup, as well as syncing in the PS4’s Bluetooth Device Manager), and the resultant support is very patchy- the PlayStation button, vibration functions, and Sixaxis functionality are all not supported, for example- but it’s a start.
Now, Sony, about letting us use our PS3 controllers on the PS4…