I think this is a matter of opinion and varies by the customs wherever you live and your own personal feelings. Yes, they are technically included and you are absolutely not REQUIRED to tip. I always tip-- we bring a couple hundred dollars in singles and tip for drinks, at meals, the maid, and for any one who provides us service that we are appreciative of! The way I see it is that some staff go above and beyond to make your stay great and I personally like to acknowledge that. There's no real "rules" on tipping- some don't at all, some do only when they receive service that they feel is above and beyond, and some tip for everything (I waitressed for too many years in college and probably over tip for everything). But it shouldn't affect your service either way.