I'd like to suggest that more users be allowed to view a blog under the private setting.
Currently, only a maximum of five users are allowed to be added to the reader list, but it would be far better to raise the limit here significantly and allow users to control their readership base this way rather than by allocating them subscriber status. If a blog were being hosted on a private server, I understand the idea of delegating subscriber status, but since wp.com is a community where each user has their own username/password, I do not see the point of allowing readers access to my dashboard, where they can view and edit their own profiles, if they can very well do so on their own dashboard.
It would be great if users were able to set their blogs as private, and then have others request to be added to the reader list (through a comment perhaps, on one public post ala livejournal), upon which the admin can click a button to "Approve" or "Reject" without having to manually enter the usernames on a seperate page altogether. Alternatively (or in addition to that), place a link or icon beside a user's name offering to "Add as reader", or something of that sort.
What say you?