I've created an RfC page on adding support for partial page caching
(edge side includes) to MediaWiki. Please add comments there if you have
any thoughts on this:
http://www.mediawiki.org/wiki/Requests_for_comment/Partial_page_caching
There is also a corresponding Bugzilla bug here:
https://bugzilla.wikimedia.org/show_bug.cgi?id=32618
Ryan Kaldari