the link to http://mirrors.jenkins-ci.org/war/latest/jenkins.war is extremely convenient.
Please provide a http://pkg.jenkins-ci.org/debian/binary/jenkins_latest_all.deb.
Debian does not care about the name of a package so having a symlink should be enough.
Pro: Updates are easier as there is now only a single link to check
Con: People may start hammering the server since checking for updates is now easy