Our intent is to allow anyone to download, adapt and make the designs for free whilst retaining the right to charge a markup on commercial manufacture / distribution. I.e.: we're not just about Open Source but also about a local making marketplace that (transparently) we make a cut from, in exchange for value offered in QA and ease of purchase.
What we have definitely found is that it is not clear what exactly "Non-Commercial" means. On the one hand, we want to approve makers who commercially re-sell OpenDesks. On the other, we don't want to stop you taking a design to a local CNC shop yourself and asking them to cut it. We'd welcome both legal instruction on the validity of that position and any steer on appropriate license text.
N.b.: if you're interested in a "purer" effort to create a public domain library of CNC-able designs, check out the next stages of the WikiHouse project: http://www.wikihouse.cc/community