"Hardware Drivers" item missing from menu

The tool is now called "Additional Drivers".

Just press Alt+F2 and type jockey-gtk. You will always open the Hardware Drivers no matter what the name in the menu is.

In 12.10 this has been merged into System Settings. You can now click on the Cog icon (Top right corner) and select System Settings. In the system section click on Software Sources. The last tab will be Additional Hardware and it will have a very easy way of managing the drivers versions and different drivers for each hardware device.

As mentioned by Søren Løvborg, you can go directly to this by typing software sources in the dash search.

The name was change to Additional Drivers as one of the One Hundred Paper Cuts. See here : Change the name of "Hardware drivers"

The principal reason for the change was that the name Hardware Drivers was confusing as the tool only manage non-free drivers and not all the drivers.