Amazon.co.uk has put up a preorder page for the Hori Tactical Assault Commander 4, revealing some details and images. You can find the photos of the controller with the media gallery located below this paragraph.
As you can see above, the Tactical Assault Commander 4 is designed to replicate the keyboard and mouse setup used to play PC games. The officially-licensed product also comes with a touch pad in addition to programmable buttons and LED backlight.
Along with the PlayStation 4, the accessory is also compatible with the PlayStation 3. There is a switch so that you will be able to change the platform compatibility.
According to the listing, Hori Tactical Assault Commander 4 is expected to come out in the U.K. on the 9th of October. It is unknown if the same product will be brought over to the North American region.
With that said, Hori did release the Tactical Assault Commander 3 (which is only compatible with the PlayStation 3) in the United States. You can check out the third iteration of the accessory with this link on Amazon.com. If you prefer using a keyboard and mouse as opposed to gamepad, you might want to check out the Tactical Assault Commander 4 on the PlayStation 4 when it launches.