JasperReports is updated quite frequently but the the JasperReports Integration toolkit is shipped with a specific version, originally 3.7.4. This is already quite outdated although the Integration toolkit didn't change it would still work against the latest JasperReports libraries. I have started to separate the libraries for the JasperReportsIntegration from the original JasperReports libraries, so now you can upgrade your installation by simply replacing the old libraries with the new ones.
Further questions will be added here as soon as they come up ;)