It would be nice if filters, as well as portlets, could be specified with a "current project" value for the Project selection, and allow a dashboard to be associated with a project. Thus, you could:

• create one dashboard with many portlets, some of them being based on filters, and then duplicated that dashboard for each project and simply change the associated project, without having to edit every single portlet and, even worse, recreating the filters so that they apply to the new project
• create generic fitlers whose output would depend on the current project (there is a notion of current project in Jira - for instance, when you click on Browse Project or when you do a quick search bug issue number)
• reports could also be generic, instead of forcing you to create a new filter for each project