C.:
Here is my take on it. I am on the extreme opposite of everyone here. My daughter is 14 now and I worked in day-care with 2-3 year old children for 20+ years. This is what I did and it is only my opinion so I hope everyone doesn't get bent out of shape.
I never "took" away the paci or bottle either. I felt like she is a baby once and when it is over it is over. In our society we are constantly saying hurry up and do this hurry up and do that, they are too old for this, does your child still do that. So she took her bottle until she was finished with it. When she gave it up then I put them away. In essence switching from a bottle to a sippy cup is no different. It is still sucking on something and carrying something all the time it is just that one has a nipple and one doesn't.
I never "took" the paci away either. She did lose it at the baby-sitters house one night and I thought I would see how it went. She was used to having three, one in each hand and one in her mouth. When these were lost, I had one in reserve, of course, in case we needed it. She would just say "Where is paci?" I would say I don't know where is it? She would respond and say "at Bonnie's houes?" That was the end of the paci, but I still have one in the drawer for a keep sake that I pull out once in a while and tease her with.
My thought is that it is the same thing as telling a person o.k. you are XXXX age and you are too old to have your mornining coffee, or your are too old to smoke, etc., but because they are adults we don't do that. These are children and we are bigger so we can "take" their comfort item from them.
By the way my daugter was 3 when she gave up the bottle and 3.5 the paci. No damage done to teeth, psyche, etc.
Like I said, just my opinion.
J.