JIRA (and Confluence) are closed systems regarding the knowledge accumulating in them. It would be great if this knowledge would be accessible by search aggregation with an external client. And vice versa JIRA could be an aggregator itself to include search results from external systems. E.g. Alfresco and A9 supports OpenSearch (http://www.opensearch.org) to do exactly that.
And given the support for open standards by atlassian this could be a no-brainer.