It seems that no one actually announced the creation of the
"newprojects" mailing list yet!
The mailing list is an announcement-only list for new Wikimedia
wikis. The way it works is that the addwiki.php script that
sysadmins use to create the wikis automatically sends a mail to the
list, so (provided there are no bugs with the script) subscribers will
get an e-mail when every Wikimedia wiki is created.
This list should be especially useful for people who need to know when
new wikis are created so that they can update their tools or scripts.
Of course, people who are just interested in knowing about new wikis
are welcomed to subscribe too. :-)