well I spoke with an IBCLC and waited awhile before finally making the decision. She assured me that it was more a question of parenting than of nutrition, which made me feel less guilty about not wanting to pump anymore. He's eating plenty food and still nurses on demand when we are together. he certainly was nursing at night, as soon as we got home, and as much as he wants on the weekends. But we'd started to notice that if he was out and about with DH, for example, he'd go all day with no interest in the bottle and was fine just drinking water. He'd gotten used to 3 3oz bottles a day at daycare, but was also sometimes only drinking one or two. I decided to just taper him down to just twice a day for a week or two, and then we decided (the daycare ladies and I) that he seemed like he could handle just having water to drink throughout the day. He'd been there long enough that they could get him to sleep without milk. They have been good about helping him learn to get to sleep without constant rocking or milk and also knowing that there's no CIO allowed, not that they;d do that anyway. I think there's also an element of peer pressure--if all the other kids are lying down and he sees that, eventually he'll be a copycat. My DS was the kid who would wake up and chatter so much that everyone else woke up too but(hehe) now he;s sorted it out and will take a 2 hour nap.
(Sidenote but this drives me nuts--if they or my DH say "lie down and put your head down" he will do it and go to sleep, no problem. Me? no way! he just laughs and reaches at my shirt and this week has started saying "nurse!")
As for your milk supply and your body, it may take a couple weeks but your body really will figure out when to make more milk in the cycle that you need it in. My sister stopped pumping for her DD (our kids are only 2 weeks apart) MONTHS before I stopped, and her DD just had more water and food at daycare and then nursed as much as she wanted when she got home. The initial reverse cycling that may happen--baby wants to nurse all.night.long may drive you nuts but it will also subside. And your body will figure out your schedule. I'd say it took about 2 weeks to not feel too full during the day when I'd normally be nursing. it DOES mean that within 10 seconds of entering the house after I pick DS up from daycare we have to sit down and nurse, but I actually really like having that time with him to reconnect and transition in to our evening.
It may be that you want to pump for a few weeks and then slowly taper off if that's what will help you feel better about the transition. There's certainly TONS of information available to give to the daycare so they handle the milk properly--it's not rocket science, they just need to be willing to learn a little bit. There are simple charts they can glance at to remind themselves and it'd probably help someone else in the long run.
Whatever you decide, just know that it's a process and you'll be able to make the decisions you need to make as you go along.