Sounds sensible to me. It also would be a worthwhile endeaver to put up a blog post summarizing what user/passwords exist in all the supported templates by default, and what options each provides to customize that, and then having linuxcontainers.org point to that blog post.
You wouldn't need to do it for all the templates yourself - I think if you put out a call for content to lxc-users you would get contributions. But a readme.debian is a great start :)
