Make of multi-domain a true multi-site feature

Drupal has a cool multi-domain feature allowing to specify a different theme for each domain. However if drupal had just a few more features allowing to differenciate each domain, it would be really nice and useful.

The themes system is very well designed for that purpose because blocks are theme-dependant and not site dependant, which means we can differenciate a site easily by creating a new theme. This is a good thing and should stay as it is.

The problem is that, in terms of site content, when you want to differenciate content available on each domain, you have to prefix your tables, which means that the content you posted on site A will not be available from site B.

It would be better if we could differenciate content by defining a Sites vocabulary. Chosing one or more terms of this taxonomy when submiting a node would publish it on the selected sites. Notice that some site networks need to publish the same story on more than one site, so it would be a multi-select vocabulary.

Additionally, it would be nice if the site settings could be customized for each domain, like it's done for the themes for the moment you have to override the variables in each domain's settings.php file.

This allows to create a sites network using a shared database with all tables shared.

I tried to do that manually by adding a Sites vocabulary, assiging it some stories and setting each Site's term path as front_page in the settings.php file, but I had no success as there seems to be some caching- related and other issues.

I posted a forum story about this a few weeks ago:
http://drupal.org/node/92675

As you can read on the forum, an intermediate way was found, by prefixing the cache variable tables, but I don't know if it will be well supported in the future releases, so I'm hesitating to go in production with it.

It looks like Drupal is not too far from that and that would be a really useful feature if it worked.

So maybe it's still possible for Drupal 5, I don't know, so I assigned version 5 beta 2 for the moment.