First off, congrats on doll of the month! You so deserved it
Second, I agree with Hayley; they way you draw hair is PHENOMENAL, but it would look more complete with a couple loose strands. Take a look at her doll thread and her tutorials; she does it really well, without drawing too much attention to them.
I also think you should change the belt, but don't scrap the idea completely; it's really part of the coloration and it helps the doll pop.
I'm a big fan of the folds in the middle of the dress; way to make a tight dress that still lets her breath a bit
I think the problem I have with the folds toward the bottom is that they seem to cut her off, particularly the second one from the bottom; I don't think it should reach all the way across her legs.
The bracelet is also a really nice touch, but I agree with Hayley on darkening the outline on the necklace; I can barely see it and wouldn't have noticed it if you hadn't pointed it out.
I really think the silver shoes tie the doll together more, even if the gold is more "Batman". although, it looks like your going with more of the Batman redesign that the grey-blue-black version, and I don't recall anything but black and some yellow (cause of the bat signal) in that.
This is just a minor thing, and it may not even be necessary, but did you already shade the base under her hair? And if so, can you do the same where her clothes and accessories hit? It helps take away the pasted on look, but this already looks very nice and not at all pasted. I'd also consider adding a strip of the back of her dress (a few pixels thick) under what we see in the front because it is asymmetrical (so a small wedge I guess is what I see).
Overall, this doll is fantastic and really only needs a few minor tweaks to make it look more complete. You've caught on, and you'v caught on fast! Kudos!