MediaWiki is an HTML-generating wiki application, like the WakkaWiki we're using now, except much better.
MediaWiki looks much more professional then WakkaWiki, and has a ton of features Wakka doesn't support, like image uploading, nicer looking page history comparisons, and automatic redirect generation.

Recent comment made by LL on the future of the wikis
http://forums.secondlife.com/showthread.php?t=58100