Hey there panter
You're right, the multisites component is right for the job, but is still limited.
I studied it, tried it, and the fact is, it does website cloning, with everything: database+files.
Now, since Joomla1.0.12 has some 3000+ files, i dislike this solution: if i have 4 languages, i don't want 12.000 files in my hosting account.
BUT
I made some twists in the code and managed to make things work after all, so that i only use one Joomla install and just switch between the databases.
I use
OpenSEF+Multiple databases+some tweaks in the index.php
The multisites component can be used just to replicate the database, it doesn't do updating. For instance it doesn't know how to only copy the non-existent modules or components from main-database to new-database, so it overwrites everything there, and thus destroys language specific settings (such as module titles) one has set in a specific database.
If you're interested in more info on this, i could post more, maybe i will even create a component to handle all these details. But it may take a few weeks
Catalin