While I haven't had a chance yet to come up with any ideas, I have a few points that might (or might not) be useful for discussion:
1. Though there's not much in the way of guidelines, I think it's valuable that the logo be usable and legible at a variety of sizes (maybe from small icon size up to web banner size). Though if the winning entry comes in created in a bitmap editor like the Gimp, I'm sure I (or anyone else) could or should produce a final version in SVG format so that it is scalable for use in a variety of resolutions.
2. It hasn't been mentioned anywhere that I can find, but I'm assuming that the logo should work on a variety of backgrounds as well. I'm assuming the primary focus is for use on the web, although you might get into labelled CD's and labelled USB keys or something as well I'd assume. This kind of goes with point #1.
3. There's been no discussion of any text to go along with it, so I'm not sure if the 'crunchbang' text itself is up for modification. I know that the current logotype is based on Helvetica (which is non-free). I wonder if now is a good time to entertain something done in a free font face. I'm also not sure if such a thin font style will be applicable to the winning logo. I think both things should work together in the end or else it might look a bit slap-dash if you know what I mean.
4. If it's valuable, maybe there should be separate threads for submissions and for logo discussion. There might be some great ideas that people come up with on paper sketches or in rough form that merit discussion or critique. I'm notorious for revamping and reworking my own ideas (ad nauseum sometimes
) So it might be valuable to have a discussion/ideas thread in addition to the submission thread so you don't scroll through 8 pages of this thread with very similar but slightly different entries. I think it's valuable to get feedback on stuff.
Anyway, some stuff to think about.