I've written a guest post on CMS Wire which was published earlier today.
In the post, I present a Google Summer of Code project that I believe many Joomla users will find useful: Native Multi-Site support.
This will give administrators the ability to set up one Joomla installation for several websites. The advantages of doing this are obvious - but it's a quite complicated matter.
Read the article here: Joomla Multi Site Support Nearing Completion