a5e64d83_ureStatus20120119____XWiki_org__Status_as_of_2012_01_19
[Feature] Performance (make XWiki faster, more responsive and less resource-intensive) [Status as of 2012/01/19] 
We've improved the speed in several releases but this is a continous fight as new features get added. For example recently we've added the Activity Stream on the home page dashboard and it's quite slow. We need to work on performance again.
Feature Status - Jan 2012 (Blog.FeatureStatus20120119) - XWiki.org
Status as of 2012/01/19