I had the same dilemma when getting room service at the Disneyland Hotel, but wound up giving the server a few dollars anyway. That was the only time I wasn't sure on tipping, the rest of the time it was usually pretty clear the times you should tip. I always leave a couple of dollars each morning for the maids too.
So basically service is included, but should I still tip the waiter or is that unnecessary? I would hate to appear rude!!