Ah, something to see!
2007/3/7, Joerg Baach lists@baach.de:
Now, to get help with questions like that, where do you recommend to look for answers? This list, #wikipedia, another mailinglist?
On this list are several people who are very familiar with MediaWiki, so I think that this list will work. There is also the list wikitech (http://lists.wikimedia.org/mailman/listinfo/wikitech-l), which is quite active, but is mirrored in the net.
As for the IRC, there is #wikimedia-tech.
Cheers,
Philipp