I've checked for name conflicts in related areas, in package repositories (FreeBSD ports, Debian's and Ubuntu's archives), major open source hosting services, and haven't found anything related. Let me know if I missed anything relevant.
I'm the team lead of the Jetpack plugin for WordPress. I've passed it upstream to our in-house counsel just for a cursory review should it conflict with trademark scope or something.
(What do I know, I'm a dev, not one of those lawyer-types)
(But as the Mozilla Jetpack thing existed before we did, and we both coexist, I'm not expecting a kerfluffle, but who knows -- I am not a Lawyer!)
If you must complain about a project called "Jetpack", point your arrows towards Wordpress[1].