I would say that more customization options are pretty much low priority at the moment. Even because the game isn't really below the average in that regard.
More is better, but I would say that more things to *do* is even better, at least for now. They're always in time to add more hairstyles.

Also, people think that "sliders" are be all end all, that's a common misconception, especially with bodies. There is a tradeoff with that kind of customization. The more you variate bodies, the more generic the animations need to be in order to fit a more generic skeleton.
Considering how nice most animations are in this game, I'd much rather keep those, and not have body customization.