On the dev list Angela Byron is mentioning a lot of multi site modules. This is an extract from the discussion followed.

patterns

Module/system configurations that can be run at any time

hostmaster

Bryght's multisite hosting managed site deployment framework, which includes http://drupal.org/project/hosting and http://drupal.org/project/provision. See
http://groups.drupal.org/hm2 for more info

autopilot

Migrate changes from dev to live

deploy

Migrate changes from dev to live. Moshe added it seems that 'deploy' is most promising. as an all purpose tool, see capistrano http://jystewart.net/process/2007/02/using-capistrano-for-drupal-deploym... ruby is only required on the source PC, not on all the target servers.

drush

Command-line tool containing a bunch of useful commands such as running cron, downloading modules, etc.

domain

The Domain Access project is a group of lightweight modules that provide tools for running a group of affiliated sites from one Drupal installation and a single shared database.

dast

It can use custom build files to do all kinds of things on the filesystem and DB. It
supports lots of Drupal friendly stuff including modules installation and install profiles as well. It could certainly be configured to handle many multisite possibilities.

GHOP #66: Review multi-site manager tools

This mentioned http://drupal.org/project/druplet apart from multisite manager and hostmaster

This listing makes me wonder. So many options will kill drupal in the end. And there is so many energy wasted on developing all these different modules doing a like thing. That is what OpenSource is too. Two many (degrees of) freedom.