The changes plugin should take an issue number in an <action> declaration. This can be hyperlinked in the report.
The link can be derived from issueTrackingUrl if it is a known tracking system (JIRA, Bugzilla, ?), but allow specification via maven.changes.issueUrl.
Additionally, a release should allow the specification of a version (JIRA), or milestone (Bugzilla). The hyperlink can point to some query about those issues, or a roadmap or something (haven't thought about that yet).
This is the first step to a more complete integration where changes might automatically suck in issues marked for a certain version.