This may have been covered before, but I just couldn't find anything on it.
I routinely "queue up" a long list of articles for future publication. Given my schedule, I can never be sure that I will be around to publish on a given morning, so the queue approach really works for me. I basically just put in a future date, flag it as "published", and save it. Works great under 1.5.
Under 2.0, it still works, but the category list generated by wp_list_cats() reflects even the post-dated articles.
For instance, if a category has 3 articles in it, but one of them is flagged for publication on a future date, it shows "3" for the article count, rather than "2".
Also, if a category only has post-dated articles in it (i.e. nothing viewable by a normal user), the category still shows up in the list.
I would think that the proper behavior would be to only show categories that have current articles in it, and the count for those categories would only reflect current articles.