Stardoll has updated the star design hair, into two parts: the basic (the old one) and curlfriend! There is also a "coming soon" section, which means they will have another type soon!
Personally, I don't really like the update because first of all, I don't have a thing for curly wigs. Second, the wigs just end up looking like the curly hair from tress up, which are a lot cheaper.
However, the wigs are much, much cheaper and the idea was very smart. I hope the next update will have pieces for straight hair!