T.,
I have to agree with most of what was said in the other advice left for you. The "12 month rule" is just a general guideline, not a rule. From what I understand from my pediatrician, you child can't use all the fat in the milk properly until abt 1 year, so it's wasted, that's why you stick with formula until then...not the other way around. Moving up to sippys and cups is a developmental thing, not a nutritional thing...so don't sweat it.
My daughter faught it. I just started to switch her middle of the day formula to milk in sippys first, since she had other food to supplement those meals (and mixed her cereal with extra formula to make up any missed calories until she started to take the sippys better, and eat better solid meals altogether). I kept the night bottle consistent for a few weeks, then made the switch. By that time, she was used to the sippys and the taste of the milk. I also used that time to change her bedtime routine from falling asleep in my arms with a bottle of formula (she is adopted - so I never nursed for obvious reasons) to a story, a song (the one I always sang) along with her sippy), then say her prayer (I say it for her at this point), then in the bed with a kiss goodnight. The sippy leaves the room with me, and she puts herself to sleep. After about two nights of temper tantrums, she has been putting herself to sleep for the past 10 mos. If she wakes in the middle of the night, she self soothes (unless something is wrong - like a foot stuck - I am sure you know that routine) and goes right back down.
Good luck. I hope this helps.
S.
Mom of two beautiful little girls 21mos and 2 1/2 yrs.