I'm with Amber -- see her post. As long as the crib is there she is going to choose that because it's what's familiar and comfortable. And while I usually would always say, "The kid's young, let her have her comfort object," this is a fundamental safety issue to me. If this is one where you have the side off so it's open on one side, that's fine, but if she is in it all night with the sides up--she's going to have problems when she does climb out. And she will.
She has not climbed out -- yet. Some night soon she's going to want to come to you in the night, or she's going to decide she wants to get something in the room, and she's going to climb. No matter how much you tell her to stay put, no matter how much she says "I'll stay here mommy," she's eventually going to climb. Well....Go look at the crib. Picture her falling from the top of the raised rail to the floor. That's quite a distance for a kid-- especially if she falls head first. My friend's kid broke her arm the very first time she tried to climb out.
Truly, going cold turkey now is not going to scar her for life; she will not remember it. If you handle the transition to the toddler bed well -- stay in the room the first few nights or even weeks, for instance, which will help her, and once you leave the room, be calm about silently walking her back to her new bed (over and over and over if needed) when she wanders out of it -- then it'll be OK. If those things scare or bother you, be aware that eventually you'll have to go through this transition and establish these new routines with her; why put it off?
I would not whisk the crib away so it's missing when she comes home one afternoon from playing; I might treat it like people do pacifiers and tell her that it's going tomorrow to some child who really needs it. Maybe she can help carry the parts to the car while you talk about the baby who's going to have it -- and then immediately take your daughter to the store to pick out fantastic new sheets and a bedspread etc. for the toddler bed (even if she already has some). Those first few nights will be tough but she will survive them and so will you. Don't be afraid to stay with her until she's asleep at first -- despite what some moms say, it does not mean she will expect you in her room when she's 10. You can gradually leave her half-awake and eventually tuck her in and leave, but if you are removing the comfort crib, yeah, you'll have to do some work for a while.
And as someone else noted -- if she is in a crib with the sides up, you can't be potty training for nighttime yet. You don't want her to have to transition on two major changes at the same time -- moving to the toddler bed AND being expected to try night training. If you move her to the bed now, you can do the nighttime training later, but if you wait on moving her to the bed, the two changes might be too close together and that's a recipe for problems with both bedtiime and pottying.