Currently, our JIRA velocity notification templates are full of ghastly constructs like:

${constantsManager.getIssueType($issue.getString("type")).getString("name")}

to access the issue type. We really shouldn't be accessing internal APIs in velocity any more than using scriptlets in JSP. We should have a wrapper object passed in the velocity context, that exposes each field (incl. custom fields) as simple ${issue.fieldname} properties.