After the first couple of drives in the new TF, I was finding that the throttle was difficult to control accurately. It was not just me getting used to a new car. Searching enthusiast forums reveals that it's not an uncommon issue. I hastily ordered a new cable from ebay, part number SBB000280. In fact, it was the first part I ordered for the car. In the meantime, I cleaned the throttle body (another possible cause of sticky throttle) but that didn't make any difference in my case.
Today, I got around to changing the cable.