There's an 8 year old issue in Bugzilla for this.[1] The Firefox team has finally put some resources into fixing it, but progress has been slow. I'm not holding out much hope -- Chrome has had this feature for a long time and it's never worked quite as well as Safari's.
A Firefox multi-touch zoom extension also exists[2], but it's not smooth enough to be useful to me (admittedly, this is on my old and slow 12" Macbook).
