I myself am interested in providing a similar service at some point in time so I've put some consideration in the services I would like to provide beyond the standard OpenACS.
Here are some of the features I am interested in
Web interface to configure e-mail (smtp,pop,imap,webmail)
Web interface to configure dns
Web interface to postgres management
Chroot SSH access (or a dedicated virtual machine)
WebDAV access (I have done some work towards this)
