Some kind of repository of templates would be good. The user should be able to browse the repo and install templates onto their server without downloading the template to their PC then uploading it.

It should be possible to view a template or edit it through the UI before installing it.

Some thought would need to be given to security, as there is potential for mischief/havoc with malicious or badly designed templates. This may mean templates being reviewed before being allowed into the repo.