>Hobbyists will also aspire to them, its going to be the hardware hackers equivalent of a lathe some weird guy
you know will have one in the shed.
That's my take on it... 'Consumer' 3D printers will mainly appeal to people who already have lathes, Dremmels, tap and die sets etc.
Another model is that of a local bureau, servicing end users and other local businesses. Our local timber yard does CNC milling for £100 / hour (but it is such a big sturdy (and expensive) machine it can do jobs quickly, so depending upon the design it only adds 20 - 40% to the cost on top of the material) but you don't hear tech sites making as much noise about an arguably more useful technology (for making furniture, shelves, children's play equipment etc), though buzz-phases such as 'virtual manufacturing', 'long tail', and 'thousands of markets of a few' get invoked from time to time.
Something can help the bloke on the street make use of these services might be devices like the Kinect- MS's new SDK (for the Windows version, not the cheaper but near identical XBOX version) could easily be built upon to scan the back of your car and give you a 2D DWG of a replacement parcel-shelf. It has the bonus of making people look like Hans Solo in carbonite. Oh, a free DWG editor, including a version for your penguins http://www.3ds.com/products/draftsight/download-draftsight/#xtor=AD-508-[swfreetools]-[middle]-[intext]-[www.solidworks.com]
Hell, even the upcoming Playstation 4 allows for 3D modelling in a way that looks like it could complement traditional packages.
Other noises are being made about 'additive manufacturing', in which related technologies are used to achieve shapes and form that are hard to make by traditional means. Substrates for catalysts are an example, since they require a very high surface area to volume ratio. Another example would be structural components with 'property gradients', such as a beam of constant cross-section but of varying mechanical proprties along its length. This is possible using Selective Laser Sintering, using materials such as titanium. Such things are used in aerospace and motorsport- but then they tend to have small production runs anyway.