I think it would be useful to have the ability for a pinned topic to take precedence over other pinned topics in the same forum so that the former remains at the top of the page at all times. For example, this has been called an "Announcement" on past forums I've seen and run. But it's different from the existing "Announcement" function currently in IPB that does not serve as a topic, nor can members reply to it.
Unfortunately, those seem to get overlooked when compared to pinned topics. But a board with a number of pinned topics might have one that is important enough to necessitate appearing at the top at all times (as is our case). I'd definitely recommend adding this function in the next upgrade if possible. Seems like an easy addition.
I'd like to suggest a feature for the ACP Statistics page. We currently can view Post stats on a daily basis (such as 1,000 posts on June 15th, 500 posts on May 1st, etc.) but I'd like the ability to track the total posts on a daily basis as well. For example:
May 1st -- 400 posts -- 400 posts to-date
May 2nd -- 500 posts -- 900 posts to-date
May 3rd -- 300 posts -- 1200 posts to-date
May 4th -- 1000 posts -- 2200 posts to -date