I worry that this kind of thing will saturate very quickly due to not enough content added in enough areas for the idea to reach critical mass. However as a counterargument, look at the popularity of arXiv. I think there’s a balance between reporting scientific progress because you enjoy doing so (and you want to increase the SNR), and because you get something out of it (publications/more research grants etc.). ArXiv is very much a case of ‘I was writing the paper anyway’. Perhaps scholarpedia may become popular amongst those who would like to write academic books about specific topics, but aren’t quite fully fledged.
No-one can argue that at the moment the site needs more content. I was wondering if anyone has considered (or been earmarked for) creating a section on quantum computing. Perhaps the information already available on Quantiki could somehow be reproduced or linked.