I don't have a problem with them, actually. I think the negative imagery displaying women as "hoochie mamas" is in the television they watch, the misuc they listen to, and the women they see half dressed walking into Walmart. The key is letting your daughter know what is and is not acceptable and not encouraging her to follow trends.
I've watched the Bratz show, and it has some really positive messages about friendship, loyalty, personal responsibilities, and ownership of your feelings and whatnot. I don't consider that to be a bad thing.