There seems to be strong support for using a permissive license on copyrightable output – check out our draft social contract and the discussion of it at Reddit. CC seems like the obvious way to go for this, we'd just have to decide on which flavour (non-commercial vs commercial, attribution vs non-attribution, sharealike vs non, etc). I suppose this might be a good thing to make use of Wordpress' polling abilities for.
The other option would be to just place our copyrightable output into the public domain. I have read that this is not always as straightforward as it sounds, but I don't know a lot about it.
For me, the more interesting question is what do we do about stuff that isn't covered by copyright, like actual ideas (as opposed to plans), which can only be protected by patent. There's some brief discussion of that in the draft contract. I don't think anybody is actually interested in "protecting" our ideas with patents, but there is some debate as to whether or not in the modern broken patent systems openess is better achieved by not patenting or patenting and permissively licensing.
This is definitely something we'll have to figure out before too long.