Kevin,
I just uncovered a HUGE issue with Confluence that just gave me a really black eye (well ok, it just embarassed me badly) with one of my clients when I tried to demo Confluence to them.
It's concerning the demo space: Demonstration space
I had my client create an account, create a personal space, gave him access to a private wiki space I created for a project I am working on for him, then I edited his personal home page to a have a link to the demonstration space above. I clicked on the link, and to my horror, I found all kinds of broken images in the demonstration space!!!!!!!
1) How can I get the demonstration space back? .... OK, with great difficulty I got an export off of http://sandbox.onconfluence.com/spaces/doexportspace.action?key=ds it was very persistent about trying to get me to create an account (which I didn't want to take the time to do), but I finally got past the constant "signup here" popup and got the export.
2) Demonstration space is created to give everyone, even anonymous users, deletion rights!!!! That is just plain dumb. That space is a great demo of Confluence capabilities, but users should not be given deletion rights! because...
3) When attachments are deleted (such as all the pictures) they do not go to the trash, nothing is logged about the deletion, and there is no way for a system admin to restore them! This is a bug that has been open in the Atlassian jira for YEARS! has all kinds of votes, and yet nothing is done to fix this. I have no idea who defaced my demonstration space, no warning in the recent changes list that I look at on my wiki on a daily basis, and no easy way to restore it....
4) In the past I've seen bugs where an automated web spider (such as Acrobat's download a website by clicking all the links to n-levels to create a PDF of a website) could delete content in Confluence. I think that got fixed, but seeing lots of the pictures gone scared me that maybe it was back. Probably no bug here, given anonymous users...
5) I just restored the demonstration space I grabbed in (1) above, went to permissions to knock out the "Remove" rights, and noticed that you guys did that for your own!!!! Smart. So make that happen automatically for me too when I create the DS: space on a fresh install.
6) I have enabled public signup, but 8 of the 10 users got taken up by people who have created no content. There is no easy way to see this from the admin interface, you just have to try deleting them one by one and see if allowed. One guy signed up for an account, created a single comment, and now the web interface will not allow me to delete him because of this. That's kind of silly, I as system administrator should be allowed to delete whoever I want. I know I can go direct to the SQL tables to delete users, but this is a bother. Web interface should allow me to force removal. I've ranted about this ages ago, but no one at Atlassian takes any action....
6.1) How about a "Delete all inactive users older than ___ (drop down list 7, 30, 60, 90) days" where inactive means hasn't logged in, hasn't created any content, etc. Perhaps showing a list of the first 10 or 20 such accounts...
7) I deleted a bunch of users to make a free spot for my client to sign up. I have no idea if I was deleting recent accounts, or accounts that have been in the system a long time.
8) Confluence administration of users is generally weak. Since my license is paying for a certain number of users, this should be a lot stronger. Here are a minimum number of features I would expect to be present:
8.1) Show the date/time a user account was created
8.2) Show date of last content added/edited
8.3) Last login date/time
8.4) Login count
9) I have been inviting other friends to use the system, but hadn't heard back from them. Maybe my user maximum number of accounts was reached a couple of weeks ago, I never noticed. The system should send to the main admin and alert "Max user count reached" or even better, "You now have 8 of 10 user accounts created, only 2 more users can be created"
(10-99) Left blank. I wasn't sure how many rants I would write before I ran out of steam.... 
100) Here are my recommendations:
100.1) Add an admin menu to delete and recreate the demonstration space
100.2) Create the DS space without deletion rights for confluence-users and especially not anonymous!
100.3) Send deleted attachments to the trash (known bug, crazy it doesn't get fixed)
100.4) Allow main system administrator to force deletion of any user (with appropriate warnings if they have created content)
100.5) add 8.1 above
100.6) add 8.2 above
100.7) add 8.3 above
100.8) add 8.4 above
100.9) The system should send to the main admin and alert "Max user count reached" or even better, "You now have 8 of 10 user accounts created, only 2 more users can be created"
100.10) suggestion 6.1
100.11) Log deletions to the "recent changes" on the dashboard, and within the space
If you would be so kind as to either make sure these get fixed, create jira bugs for each of these things, or point me to existing bugs for all these, I will happily vote for all of them. Alas, I don't have time to do all the individual bug creations myself, as just discovering these issues, fixing them, and documenting them for Atlassian, has already used up 2 hours of a day when I didn't have the time to spare. I think I've done my part, can you guys do your part of at least making sure all these things I found get logged to be dealt with someday, if not in the next version?
Much appreciated,
Garnet