Hi,
My oldest had her passy until she was 3, we tried everything to get rid of it. We cut it down, gave it to the dog, threw it away cold turkey. Always she got it back! Finally at 3 she went to the dentist and he told her it was bad for her teeth, and she threw it away herself. Now my 2nd child is 2yrs old and still has hers, I think that when they are ready they will give it up, it has been a security thing for both of mine. Take heed though, we only get it at bed time after a certain age, I don't think a 3yr old should be out in public with one in their mouth. If you choose to take it away now and your child doesn't have a problem with that go for it, some of my friends kids never cared a thing about the passy they were content without it.
R.