I totally agree about it being where miniature design is going to be heading, At the moment the price point for printing is a bit prohibiative for the casual user to run off armies worth of printed figures, but as with all technologies it will improve in quality and become cheaper over time.
With Zbrush you can make incredibly detailed organic models so there's really no limit to how detailed the models can be, the printing end is still catching up but it's gotten really good if you have the budget.
These I'll be printing out then cleaning up to use as masters for casting.
I doubt that the 3d modelling will ever completely replace scratchbuilding by hand as there are a few things that are easier to do by hand than on computer but the precision that 3d gives for mechanical parts is amazingly good. It's very fast to clone parts and recycle them between models, once you have a working library of parts you can slap together models incredibly quick.
It'll take a long while but eventually I want to work up to this level of detail: