According to Japan's Dengeki PlayStation magazine, it is rumored that Sony will soon be releasing a new controller, the Dual Shock 3. This new controller will be the same size and shape of the Dual Shock 2, but will have rumble technology included. A welcome addition, as the lack of rumble has been one of the main complaints, and perhaps cons, of the PS3.
The new controller is said to debut around the same time as Gran Turismo 5 Prologue, which should be sometime in October. The controller has been featured on the Japanese GT5 website, and will be fully functional with the game.
There is no word yet as to whether games will be able to utilize the rumble feature if they were released prior to the controller, but be sure to check back for more information as it becomes available.
As usual, however, it's best to wait for official confirmation before getting your hopes up.