Vernon Thommeret wrote:

Is there an easy way to change the names of the default namespaces and have all the existing pages migrated over? Specifically, I'd like to change "Talk" to "Comments" and "User_talk" to "Wall".

I believe $wgExtraNamespaces can be used for this purpose starting with MediaWiki 1.8.0. Something like:

$wgExtraNamspaces[NS_TALK] = 'Comments';

-- Tim Starling